Jump to content


Welcome to Ultimate Subaru Message Board, my lurker friend!

Welcome to Ultimate Subaru Message Board, an unparalleled Subaru community full of the greatest Subaru gurus and modders on the planet! We offer technical information and discussion about all things Subaru, the best and most popular all wheel drive vehicles ever created.

We offer all this information for free to everyone, even lurkers like you! All we ask in return is that you sign up and give back some of what you get out - without our awesome registered users none of this would be possible! Plus, you get way more great stuff as a member! Lurk to lose, participate to WIN*!
  • Say hello and join the conversation
  • Subscribe to topics and forums to get automatic updates
  • Get your own profile and make new friends
  • Classifieds with all sorts of Subaru goodies
  • Photo hosting in our gallery
  • Meet other cool people with cool cars
Seriously, what are you waiting for? Make your life more fulfilling and join today! You and your Subaru won't regret it, we guarantee** it.

* The joy of participation and being generally awesome constitutes winning
** Not an actual guarantee, but seriously, you probably won't regret it!

Serving the Subaru Community since May 18th, 1998!

Guest Message by DevFuse
 

Photo
- - - - -

Timing belt failure and head removal


  • Please log in to reply
22 replies to this topic

#1 skibumm100

skibumm100

    USMB Regular

  • Members
  • PipPipPip
  • 67 posts
  • southern NH

Posted 07 January 2007 - 12:45 PM

It looks like I've had a timing belt mishap on my 98 Legacy GT 2.5 DOHC. Compression test shows zero on both passenger side cylinders and 120-150 psi on the driver's side cylinders with the engine cold. I'm thinking of doing the timing belt, timing belt tensioner and pulley, water pump, oil seals on the front of the engine, checking the oil pump and pulling the PS side head to see what needs to be done to fix it (new valves or head replacement). It sounds like I can make a tool for the crank bolt removal from a 2-3/8" socket. It also sounds like I don't need the tool to hold the cam sprockets in place on the driver's side either if I rotate them in the proper direction after removing the belt. The question I have is regarding removing the cylinder head on the passenger side w/o removing the engine. Can I get the head off with the engine in place?

#2 Legacy777

Legacy777

    Moderator

  • Moderator
  • 12,563 posts
  • Houston, Tx

Posted 08 January 2007 - 01:10 PM

You can get the heads off without removing the engine, however it is a little tight. Some people prefer to pull the engine since it makes working on the engine that much easier.

#3 grossgary

grossgary

    Elite Master of the Subaru

  • Members
  • 19,612 posts
  • WV

Posted 08 January 2007 - 01:19 PM

are you verifying a timing belt failure by doing a compression test? you sound unsure "it looks like". you wouldn't have any compression on any cylinders if the timing belt broke. or did you install a new belt and get those compression readings? my friend has repaired two broken timing belt 2.5's and said he only need to replace a couple valves, the heads were otherwise fine.

does it have the original headgaskets on it? if so then i'd probably plan on replacing both headgaskets if you're going that far anyway. make sure none of the tensioner pulleys are rough or noisy, they can cause the belts to fail.

#4 Tiny Clark

Tiny Clark

    Certified Subaru Nut

  • Members
  • 807 posts
  • Germany

Posted 08 January 2007 - 01:32 PM

I'm curious too, how did you check the compression with the belt broken?

#5 nipper

nipper

    Semi Elite Master of the

  • Members
  • 17,541 posts
  • Long Island NY

Posted 08 January 2007 - 01:52 PM

:confused:

Well since its been bought up, so am I

nipper

#6 Skip

Skip

    Flatuous Blather

  • Moderator
  • 8,991 posts
  • Latrobe, Pennsylvania

Posted 08 January 2007 - 02:49 PM

Possibly
valves in cyl 2 and 4 are closed and almost closed
thus the pressure diff.

the cam will tend to settle in this condition due to
the valve spring tension.

valves in 1 and 3 are bent or open


Just a WAG

#7 johnceggleston

johnceggleston

    Lite Master of the Subaru

  • Gold Subscribers
  • 6,188 posts
  • Virginia

Posted 08 January 2007 - 04:28 PM

this is the guy nipper warn about the OWOWOWOWOW factor when checking spark.


http://www.ultimates...85&postcount=31

#8 skibumm100

skibumm100

    USMB Regular

  • Members
  • PipPipPip
  • 67 posts
  • southern NH

Posted 08 January 2007 - 06:59 PM

Sorry about that guys.:-\ I should have explained the troubleshooting part a little more in this post to start with. The belt is not completely broken. I don't have it apart yet so I can't tell for sure, but I suspect I'm missing a few timing belt teeth. Why it didn't wreck both sides I don't know. I pulled one the passenger side timing belt cover back far enough to peek behind it and had my wife crank it over. The sprockets turn but I've got no compression on the passenger side cylinders.

grossgary- I'm leaning toward pulling the engine and just doing the known problem areas for this engine.....both head gaskets, timing belt, water pump, oil pump o-ring, tesioner, any suspect pulleys, oil seals.....basically the works. It just seems like a lot of work for a couple of bent valves (probably).

I got the garage cleaned out yesterday so I can fit a car in there. Had my wife help me push the thing in backwards. I need to see if I can pick up an engine hoist tonight. One of the nice folding ones if the price is right. If not, I have a guy at work who will lend me his.

Should I just buy the whole engine overhaul gasket set? Will it have all the little o-rings for the oil pump and cam seals, etc? It's $183 and it sounds a little steep compared to the individual parts price. Head gaskets are only about $30 each...that leaves $123 left for o-rings and lip seals????? What about the oil separator plate? All I can find on GenuineSubaruParts.com is a "baffle plate". Is that the same thing? Are there other recommended places to get this stuff? Sorry about all the noob questions. I just don't want to get in the middle of the job and find out I'm missing a seal. Or worse, get finished and find out I should have changed "X" while I had the engine out. Thanks for your patience. :)

#9 bgambino

bgambino

    Subaru Nut

  • Members
  • 594 posts
  • new york

Posted 08 January 2007 - 10:22 PM

Sorry about that guys.:-\ I should have explained the troubleshooting part a little more in this post to start with. The belt is not completely broken. I don't have it apart yet so I can't tell for sure, but I suspect I'm missing a few timing belt teeth. Why it didn't wreck both sides I don't know. I pulled one the passenger side timing belt cover back far enough to peek behind it and had my wife crank it over. The sprockets turn but I've got no compression on the passenger side cylinders.

grossgary- I'm leaning toward pulling the engine and just doing the known problem areas for this engine.....both head gaskets, timing belt, water pump, oil pump o-ring, tesioner, any suspect pulleys, oil seals.....basically the works. It just seems like a lot of work for a couple of bent valves (probably).

I got the garage cleaned out yesterday so I can fit a car in there. Had my wife help me push the thing in backwards. I need to see if I can pick up an engine hoist tonight. One of the nice folding ones if the price is right. If not, I have a guy at work who will lend me his.

Should I just buy the whole engine overhaul gasket set? Will it have all the little o-rings for the oil pump and cam seals, etc? It's $183 and it sounds a little steep compared to the individual parts price. Head gaskets are only about $30 each...that leaves $123 left for o-rings and lip seals????? What about the oil separator plate? All I can find on GenuineSubaruParts.com is a "baffle plate". Is that the same thing? Are there other recommended places to get this stuff? Sorry about all the noob questions. I just don't want to get in the middle of the job and find out I'm missing a seal. Or worse, get finished and find out I should have changed "X" while I had the engine out. Thanks for your patience. :)



I would get the whole set...I am currently assembling my 96 DOHC 2.5. Had head gasket problem.....My gasket set was 250.00....why is yours 183? (mine was mail order from genuine subaru parts.com)
I spent about 900 in parts...got all new pulleys which are not cheap (this drove up my costs) as well as tensioner, water pump, wires, you name it. Yes, for some reason they call it a baffle plate but the label on the bag calls it a separator plate. One weird thing about the new metal plate is that it is much thinner than the plastic one--but more importantly, the old one had chamfers at each bolt hole because the machine screws are flat heads (conical shape)....the new metal plate has NO chamfer. I did not realize this when I put anerobic sealant on it and slapped it on...i just used the chamfered flat head screws...seemed to tighten okay. But the anal person that I am went out this afternoon and bought plain hex head bolts with washers and replaced them. I did not see a gasket under the plastic plate and so I just used sealant under the new plate (anyone know if there is supposed to be one?)

#10 grossgary

grossgary

    Elite Master of the Subaru

  • Members
  • 19,612 posts
  • WV

Posted 08 January 2007 - 10:31 PM

make sure you get the new Subaru gaskets. i wouldn't go aftermarket on these.

#11 skibumm100

skibumm100

    USMB Regular

  • Members
  • PipPipPip
  • 67 posts
  • southern NH

Posted 09 January 2007 - 08:12 AM

Thanks for the replies. If you look up the gasket set today @ SubaruGenuineParts.com, the 96-98 2.5 DOHC Overhaul Gasket Set retails for $250 but their price is $183.

I was thinking or replacing the crank sprocket as a minimum plus the tensioner and any other sprockets or pulleys that look or feel iffy. I picked up my folding 2T engine hoist from Pep Boys last night. $139 minus $20 rebate makes it $119 for the folding one (no sales tax). Made by Big Red. Probably a Big, Red piece of offshore crap but I only need to pull two engines with it at the present time. Hopefully, the count doesn't go up! Putting the Bronco and Saab 9KT back on the road today. Should be enough cars to get me past my repair job.:burnout:

Thanks again guys. I'll be posting back on a regular basis asking stupid noob questions. :confused: The shoe is on the other foot for me as I'm usually answering Buick GN questions, not asking them.:burnout:

#12 bgambino

bgambino

    Subaru Nut

  • Members
  • 594 posts
  • new york

Posted 10 January 2007 - 11:10 PM

Thanks for the replies. If you look up the gasket set today @ SubaruGenuineParts.com, the 96-98 2.5 DOHC Overhaul Gasket Set retails for $250 but their price is $183.

I was thinking or replacing the crank sprocket as a minimum plus the tensioner and any other sprockets or pulleys that look or feel iffy. I picked up my folding 2T engine hoist from Pep Boys last night. $139 minus $20 rebate makes it $119 for the folding one (no sales tax). Made by Big Red. Probably a Big, Red piece of offshore crap but I only need to pull two engines with it at the present time. Hopefully, the count doesn't go up! Putting the Bronco and Saab 9KT back on the road today. Should be enough cars to get me past my repair job.:burnout:

Thanks again guys. I'll be posting back on a regular basis asking stupid noob questions. :confused: The shoe is on the other foot for me as I'm usually answering Buick GN questions, not asking them.:burnout:


Just looked it up and here is what is says:

OVERHAUL gasket set, All Models - 2.5L, 1996-98 - 2.5L, 1996-98 1996 $347.43$0.00$254.32Engine - Overhaul gasket set

#13 skibumm100

skibumm100

    USMB Regular

  • Members
  • PipPipPip
  • 67 posts
  • southern NH

Posted 11 January 2007 - 08:18 AM

That's wierd. I tried to double check but I can't get on the OEM parts site. Can't get on 1stsubaruparts.com either. It was down for me yesterday too.

#14 skibumm100

skibumm100

    USMB Regular

  • Members
  • PipPipPip
  • 67 posts
  • southern NH

Posted 12 January 2007 - 04:39 PM

Placed my order for my parts from GenuineSubaruParts.com. I hope to tear into it this weekend and do an autopsy. I'll post back what I find. I called my local Subaru dealer to see what they would charge for the parts and they charge MSRP. He said they don't make much on engine parts. Of course he also told me the woodgrain trim in the interior of my 98 GT must be aftermarket because they didn't come with woodgrain from the factory. A tip of the hat to Jamie SubaruGenuineParts for saving me beaucoup bucks, even after S&H.:banana:

#15 eventoday

eventoday

    USMB is life!

  • Members
  • 125 posts
  • denver

Posted 13 January 2007 - 01:05 AM

last year i had a tensioner blow up on my 2.5 dohc. i pulled the engine and rebuilt everything. the car had 180000miles. now i wish i would have just spent the 900$ and bought a used jap engine with 40000 miles.
don't know how many miles are on your gt

just a thought

jake

#16 skibumm100

skibumm100

    USMB Regular

  • Members
  • PipPipPip
  • 67 posts
  • southern NH

Posted 15 January 2007 - 10:35 AM

Used may have been the way to go. I got the engine out yesterday and got it partially dismantled. The autopsy is as follows:

The bullet appeared to enter through the left shoulder and........OOPS! Wrong autopsy.......let's see ......it's here somewhere......Oh, here it is.....it looks like the lower left geared idler failed and the right (PS) cams jumped time. This allowed the piston too smack the exhaust valves on the right rear cylinder (I forget which number that is). Both valves are bent and won't close. It's like the story of the three bears:

Papa Bear said, "Someone's been changing my timing belt."

Mama Bear said, "Someone's been changing my timing belt."

Baby Bear said, "Someone's been changing my timing belt, and they used aftemarket parts, didn't change all the idlers, screwed up two of the cam sprockets and got debris in the engine and messed up one of the cam bearings and cam journals."

It appears this engine has been worked on before. Way too many of the bolts were WAAAAY too tight. The flange is damaged on the left side intake cam sprocket. Teeth are fine and it doesn't rub on that flange so I think this will be OK. Right side exhaust cam sprocket has damaged teeth from the previous "repair". Needs to be replaced. The geared idler on the lower left spit the bearing out and just about seized up. This is what caused the failure. The lower right idler appears to have been replaced during the last failure/repair. I suspect it caused the failure last time. The top right idler is very noisy. When removing the cams on the right head, we noticed bearing and cam journal damage on the center bearing of the intake cam. Looks like a piece of debris came up through the oil hole and got lodged between the bearing and the cam. The rest of the bearing and the journal looks OK. The engine must have pretty good oil pressure or this would be a lot worse. The two bent valves will need to be replaced. I will probably lap all of the valves while I've got the heads off. Since these are overhead cam engines, can the valve clearance be set on the bench? Is the "special tool" for pulling valve shims needed or is there another way to change them?

#17 Skip

Skip

    Flatuous Blather

  • Moderator
  • 8,991 posts
  • Latrobe, Pennsylvania

Posted 15 January 2007 - 11:14 AM

Posted Image

#18 skibumm100

skibumm100

    USMB Regular

  • Members
  • PipPipPip
  • 67 posts
  • southern NH

Posted 15 January 2007 - 11:30 AM

Very....just lower and to the right.:-\ Question about timing mark on the harmonic balancer.....is there supposed to be a mark on the harmonic balancer so you can use the ignition timing scale on the timing belt cover? I couldn't find any notch or mark on the balancer at all. No way to tell when you're at TDC with all the covers on.......odd.

#19 skibumm100

skibumm100

    USMB Regular

  • Members
  • PipPipPip
  • 67 posts
  • southern NH

Posted 09 March 2007 - 04:51 PM

Update time:

The wheels of progress move slowly at my house. I got the engine all apart and took the heads in and had them do a valve job and replace the two bent valves. I bought two more exhaust valves because they looked like they hit the pistons also. It turns out they were not bent when they were checked by the machinist so they were reused. One head was OK but the other was not flat by 0.004 so it was shaved. All the valves were ground and the valve lash was set on the bench. After torqueing the heads in place I checked the valve lash again and found (3) out of spec. I was able to resolve one by swapping a shim from one of the other two that were also out of spec. This left me in need of two shims. My local feeble Subaru dealer said he doesn't have shims in the shop and that they have to order them when they do a valve adjustment. This sounds like total hooey to me but they have been so lame so far that it wouldn't surprise me. I went to work and got some brass shim stock and cut two pieces to fit between the factory shims and the bucket. Checked and double checked the valve lash and it was in spec. Replaced all suspect idlers (all except for one), new water pump, front and rear main oil seals, oil sep plate, tranny input seal, metal heater line, timing belt tensioner and pulley, cam sprocket, etc, etc, etc. Installed the engine and realized I had misplaced or thrown out the old fuel filter. Picked up a new one and cranked it over for a little while with the coil pack plug disconnected to get some oil in it. I tried to start it up. Car sputtered and then fired up. Then stalled. Repeat this a few times. The car throws a code. I remember that I didn't tighten the gas cap. I get the car started but it doesn't want to stay running. There is a clatter coming from the PS cam cover. When I assembled the heads I (and the machinist) used liberal amounts of assembly lube. About the consistency of frozen maple syrup. Is it possible that, due to the cold temps in my garage (around freezing), that the valve buckets could not follow the cam profile fast enough due to friction and allowed too much clearance between the valve shims and the cam lobe and now the shims fell out of the bucket? Also, is there an interlock for oil pressure in the fuel pump circuit that might be killing the engine?

#20 nipper

nipper

    Semi Elite Master of the

  • Members
  • 17,541 posts
  • Long Island NY

Posted 09 March 2007 - 04:59 PM

Update time:

The wheels of progress move slowly at my house. I got the engine all apart and took the heads in and had them do a valve job and replace the two bent valves. I bought two more exhaust valves because they looked like they hit the pistons also. It turns out they were not bent when they were checked by the machinist so they were reused. One head was OK but the other was not flat by 0.004 so it was shaved. All the valves were ground and the valve lash was set on the bench. After torqueing the heads in place I checked the valve lash again and found (3) out of spec. I was able to resolve one by swapping a shim from one of the other two that were also out of spec. This left me in need of two shims. My local feeble Subaru dealer said he doesn't have shims in the shop and that they have to order them when they do a valve adjustment. This sounds like total hooey to me but they have been so lame so far that it wouldn't surprise me. I went to work and got some brass shim stock and cut two pieces to fit between the factory shims and the bucket. Checked and double checked the valve lash and it was in spec. Replaced all suspect idlers (all except for one), new water pump, front and rear main oil seals, oil sep plate, tranny input seal, metal heater line, timing belt tensioner and pulley, cam sprocket, etc, etc, etc. Installed the engine and realized I had misplaced or thrown out the old fuel filter. Picked up a new one and cranked it over for a little while with the coil pack plug disconnected to get some oil in it. I tried to start it up. Car sputtered and then fired up. Then stalled. Repeat this a few times. The car throws a code. I remember that I didn't tighten the gas cap. I get the car started but it doesn't want to stay running. There is a clatter coming from the PS cam cover. When I assembled the heads I (and the machinist) used liberal amounts of assembly lube. About the consistency of frozen maple syrup. Is it possible that, due to the cold temps in my garage (around freezing), that the valve buckets could not follow the cam profile fast enough due to friction and allowed too much clearance between the valve shims and the cam lobe and now the shims fell out of the bucket? Also, is there an interlock for oil pressure in the fuel pump circuit that might be killing the engine?


No oilpressure switch interlock.

When it starts, how long does it run for, and is it a stumble run or a regular run.

That clatter .... which Timing belt idler did you not replace?

was the tensioner installed properly

Double check the timing, it can be off, as it happens to the best of us.

nipper

#21 grossgary

grossgary

    Elite Master of the Subaru

  • Members
  • 19,612 posts
  • WV

Posted 09 March 2007 - 04:59 PM

i think i'd start with a compression test to make sure everything is in properly in place. are the cams and timing belt all set dead on? they can not be off, even by a little or it will do what you're talking about.

check compression, spark and fuel and let us know.

#22 skibumm100

skibumm100

    USMB Regular

  • Members
  • PipPipPip
  • 67 posts
  • southern NH

Posted 10 March 2007 - 08:42 AM

I found the problem with the stalling. I missed one hose connection. I didn't have the IAC valve hose connected to the air box so the MAF wasn't seeing the airflow going into the IAC. The code it threw was the Evap Canister Solenoid Valve code. I cleared it and it hasn't come back. I think that was the loose gas cap that did that. After connecting the hose, the car will run and not stall. The only idler I didn't replace was the lower left idler because is was fine. All others were replaced. When I installed the belt, all the marks lined up and the tooth count was on the money. New tensioner and pulley, too. My car is a 98 but the tensioner is the old style. Makes me wonder if the engine hasn't been changed. I haven't done a compression check yet. I did pull the PS cam cover and expected to see some shims out, but not the case. I rechecked the valve lash and found several out of spec. I had the valves ground and a couple replaced so I expected some changes after everything settled in. I had one get tighter on me. It's an intake valve and it's only at 0.006". Most of the others got loose. I put the cam cover back on and started it back up and it still clatters like crazy. The DS is pretty quiet. I think I will need to go back and reset all the out of spec valve clearances. Some are 0.013". The first time I set them, the heads were torqued to the block and everything was covered in assembly lube. I suspect the assembly lube has been washed out of the cam bearings and the clearances have opened up slightly. I will be doing it in the car so this should be a lot of fun. I still need to do the comp check.

#23 skibumm100

skibumm100

    USMB Regular

  • Members
  • PipPipPip
  • 67 posts
  • southern NH

Posted 16 March 2007 - 01:20 PM

OK, I reset the valve clearances. Put it back together. Started it up and it made a little noise. Then it made a lot of noise. Then it stumbled, made a racket and and quieted down again. I shut it down. Took it apart again and found it had spit out a shim and broke it in half. I think the bucket had a burr or something and hung up allowing enough clearance for the shim to fall out. While it was falling out, the cam came around and caught it and broke it in half.

I started over and measured all of the lashes again. Wierd. On one valve I measured the valve lash. Measured the shim, calculated the required thickness for the new shim, bought it, installed it........and got the same clearance as before. It doesn't make any sense. Now for the bombshell.......I took my digital caliper and measured my feeler gauges. Each feeler gauge was 1.5 to 2 thou thinner than what was labeled on the feeler gauge blade. All of them.... on both sets of feeler gauges I own. I checked a set of "three letters and starts with F" (it's brand name, not a slur) feeler gauges at work. They were also thinner than marked by 1 to 1.5 thou. I had our machinist double check my measurements. Same results. So, in short, I wouldn't get too anal about your valve clearance numbers. Check your feeler gauges before you use them. I expect a lot of people are using feeler gauges that aren't correct. Does anyone have an factual reason as to why the feelers were consistently thinner than marked? I put it back together using a feeler gauge 0.002 thicker than the required measurement. It sounds like I have one vlave that may be too big a clearance. It's a little noisy on cold start up. After it runs for 20-30 seconds it quiets down some and after the car is warm, it's quiet. Can't hear it at all. I'm going to run it for a month or two and then pull the cam covers again and re-check. Then I should be good to go until it get retired.




0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users