Jump to content
Ultimate Subaru Message Board

1.8L head gasket leak


Recommended Posts

Hello,

I got a loyale wagon with 160k miles........

the passenger side rear head gasket leaks oil.....

I think this also creating a drop in oil pressure

when motor revs below 3000rpm.

I was figuring on replacing the gasket....

but, I just want some insight as to how to approach the

problem.... Accomplishing the work is not the issue... As

for I have been working on these puppies for a while now......

The issue is, I don't want to do this twice.......

I would like to solve problems not the symptoms.

So here is my question..../questions..:

Am I wasting my time just replacing the gasket...

Should i resurface the head?

Is there a laymans way to check the head for warpage?

What about Blow by?

could the oil leak be caused a result of blow by?

How can I check If the motor has blow by?

So IF any one out there can provide me with some

wisdom regarding approaching the situation... I would

be much abliged.....

Thanks, Micky

Link to comment
Share on other sites

I would say you are correct in the gasket causing low oil pressure. I bet when you rev the car up the oil gauge goes up and when you let off the gas the gauge falls to zero. not holding pressure.

 

make sure it is not the cam cover leaking oil, as it could easily be mistaken for something else. My rx had a leak and I thought for sure it was coming from the turbo, turns out it was the back side of the cam cover.

 

If you are certain it is the head gasket then it wouldn't be a waste of time to replace it at all. Under normal circumstances I would say don't worry about resufacing the head just use a razor to get all the old gasket off.

I don't think that blow-by is the source of the problem at all. 160k on the stock head gaskets, probably just weakened and finally went. Don't know of any laymans warpage test either.

 

keep an eye out for a crack in the head between the valves, as this is normal. The ones you have to watch for are the ones that go into the exhaust port as they may billay out and start leaking coolant into the exhaust.

 

It sounds to me like you pretty much know what to expect though so good luck with it

Link to comment
Share on other sites

Thanks,

myossfeece.

 

Do you think while I am there.... replacing the head gasket

that I should replace the o-ring and the funny looking

(gasket/rubber pump chamber seal thingie bob)

I don't know the name of the part... but it is in there

when you pull out the oil pump........

I figure I will do the camseals and the front seal on the crank...

 

I also was wondering where I will find the camshaft cover that you spoke about... I would like to check and see if this is leaking

as well or if this is possibly the cause.....

 

thanks, Micky

Link to comment
Share on other sites

the cam covers I spoke of are on the side(s) of the motor. they are the valve covers that say subaru on either side of the block. you can get cam cover seals and grommets in a kit for something like 20 bones. they are at napa.

 

Yes the oil pump shaft seal is a good one to replace. If you were to go as far as pulling the oil pump off the motor there would be three seals to replace. the mickey mouse seal, the "o" ring seal, and the pulley seal. it probably isn't neccessary to replace all of them but with 160k it would suck to get it all together just to have an oil seal failure.

 

it would aslo be a good idea to service the cam seals and the front crank seal, just to get it done and out the way.

 

if you are already gonna have the motor that far apart, have you ever thought of running open t-belt covers? I am running open covers and have about 10,000 miles on open belts and have had no trouble. if you were to run open covers the only piece I would install is the inner cover between the water pump and the alterator, because that is the only spot the belt would be exposed to debri.

it will turn a two hour timing belt job into 20 min on the side of the road. right after mine was done it broke a belt but it was improperly tensioned on the motor it came off of, and then I put the RX belts back on it on the side of the road and have gone 10k trouble free.

 

sorry if I got off subject on ya but none the less good luck.

Link to comment
Share on other sites

its normal for the oil pressure to be rally low below 2500 rpm. it should be around 35-45 at 2500 rpm is considered normal operating, nothing for alarm..

 

there is an o-ring between the head and the CAM TOWERS, on the mating surface.

 

the cam covers that myoss feece speaks of can generically be referred to as a "valve cover"

 

i have seen a valve cover so bad i thought it was a bad o ring under pressure. the cam/valve covers seal will get brittle, and crack, therefore leaking.

 

i would bet the head gaskets are fine, but it wont hurt to re-do them anyway for safe measure. (i suggest pulling the motor, and doing both sides, complete gasket set if you decide to do so)

Link to comment
Share on other sites

Hey, Thanks all!

 

The info is good for the brain...../cell.........

I'll check the heads for warpage as how was

previously described.... I have a carptenters square

and feeler gauges... That will be good..................

The cam covers! oh,, yeah... OHC...... Yeah, I guess

I was still calling them valve covers for all the damn years....

used to workin' on those cast iron engines...........

As for the micky mouse seal... I'll replace that

seal..... Looks like i'll do all the front seals and the head

gaskets and cam cover and the intake.....

It is a tough call where do you stop.........

I remember my other subie....... rebuilding the front end.....

it was cheap..... but i ended up replacing any of the parts

that you would replace....... at the time ... a grand later.......

Yeah, I probably need a clutch in this car too....... 160K

I think she said it was the original clutch...... Ijust bought

it....... It was either me or the junk heap for this pup.....

Well, I said it looks better than what I have been driving....

and I won't have to take a bath any more while I drive it while

it is raining........... funny thing I bougth the exact same car:

year model and even the color.... I got the fancier version now

roof racks auto seatbelts...... I seems geared different too...

this one came from Colorado......... What do you's think.......

makes sense.... northeast isn't like Colorado.........

Do these motors and tranies pull out together pretty well???

you know....... pull the motor and the tranny right out up through

the engine compartment as one piece????????

Maybe that is what I will do...........

and get that clutch while I am at it......

 

Micky

Link to comment
Share on other sites

DO NOT PULL THE MOTOR AND TRANS AS ONE UNIT. or you will find that you will be taking it out at a near 90 deg angle, afte you unbolt half the frame

 

pull the motor out, that will access you clutch, and the time it takes to pull the motor will save you time trying to work on the heads with the motor in car

 

with the motor out, you can set it in a 5 gal bucket for a stand, and do the heads and front end

 

DO NOT WORRY ABOUT THE CACKS BETWEEN THE VALVES. the cracks between the valves are normal, and expected. the cracks can go down to the VALVE GUIDES, dont worry. as long as the cracks are not splayed open. there is no water or oil passages in this area, only a valve seat may drop out if the cracks are WIDE OPEN

 

heads generally are not warped, i have neverhad problems with warped heads, and have used some QUESTIONABLE heads with NO PROBLEM

 

leave the tranny in the car

 

if you do pull the trans, take the motor out first. the axle pins on the inner end are 3/16" inch dont use 1/4 inch or the punch will get STUCK

Link to comment
Share on other sites

Thanks,

For the info again......

Yeah.... I'll pull the motor and do the heads

outside of the car..... that will make my life easier

for sure.........

My question reagrding leaving the tranny in ......

the vehicle has a standard transmission...... will the input shaft

give me any problems on the install...

for example no room to slide the input shaft/tranny into

clutch assembly/flywheel...... due to small engine compartment.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...