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Guest Message by DevFuse

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Subie sounds like Peterbuilt and other post repair woes

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7 replies to this topic

#1 Farewelltoernest



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Posted 04 July 2014 - 07:33 PM

Hey everyone, I also posted this on the forester forums, just need as much advice as I can get. I respect ya'll a ton.


Happy 4th of July guys! 
I am in dire need of some diagnosis for this poor trooper 98 DOHC M/T Forester (236,000)
I'm going to start by telling you that I'm pretty sure these problems are my fault, and not something that would naturally happen to the car over time. 
She also wants to go- and fast. No resistance or hesitating when accelerating. If these problems weren't here, this Subie would be a dream.
I've just completed my first head gasket replacement. It was hellish, and I was foolish to think it would all work out great.. So I'm just going to list the symptoms and hopefully we can narrow it down from there. All advice appreciated.
1. She sounds like a diesel. Not like a TDI Volkswagon, but like a rig. It's louder on the Drivers side.
      There is an exhaust leak at the manifold right now- It smells awful and the smoke comes out of both sides. Like an idiot I used RTV on the block side of the gaskets, which were rather flimsy non OEM gaskets to begin with. My plan is to replace them with OEM's, but I don't know if that is the cause of the loudness. Intake manifold leak? Here are some vids:
2. O2 Sensor wires/Mystery Sensor
    So while I was removing the nuts for the exhaust manifold, I was expecting some sort of center exhaust support to back me up- instead the whole thing dropped. It ripped out 3 wires out of the front o2 sensor and I have no idea where to put them in the 3 wire terminal. There's one black wire with a gold blade, and 2 white ones with silver blade. Also, you'll notice a small, gray sensor plug in the 2nd photo in front of the o2 sensor terminal. Where does it go? It has no slack and I can't find anything to plug it into near the big bracket.
3. Overheating
    According to the temperature gauge (which is acting bizarre anyway) She gets hot rather quickly. If leaking coolant at all, only in  small drips coming from the lower radiator hose. Rear drivers side hoses connected and clamped. Filled up with fresh, clean coolant. Overflow tank is full. Car has plenty of new 10w-30 in it. Full on the dipstick. I don't understand it.
4. Electrical issues
     So in the final stages of putting the car back together, I managed to snap the bolt of the positive terminal on a 1 year old Bosch alternator.. and only had enough money to replace it with a frickin' duralast. The battery light is on on the gauge cluster. But then again, so is the brake light (it doesn't turn off now, the reservoir is full of dot3), and the temp gauge occasionally goes nuts, as in, at the bottom while stopped at a light, and a hair away from the red while driving, and then in the middle, and then at the bottom again.
I am going to have the duralast (rebuilt in mexico and "tripple tested for quality assurance") alternator tested, but due to the other issues I feel like it might be an issue with the ground cable. Is it in the right place? Here is a picture of it (in between starter and bolt head, not starter and block.)
5. Mystery pieces
              Anybody know where these go and if they are important??
I love this car to death you guys. I want it to live a long and happy life. Please help me out here.

#2 lmdew



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Posted 04 July 2014 - 07:45 PM

Well to begin with, the engine will have to come out as the HG go on Dry.  If you put RTV on they are junk and you may have caused oil system problems if the RTV got into the oil passages.


I'd swap to a good 2.2 and be done with it.


The last pic, the two brackets, one is for the Alternator bolt and the other hold the O2 sensor wire and goes on the lower passenger side stud.

#3 Farewelltoernest



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Posted 04 July 2014 - 09:40 PM

Hey, thank you for your reply!

HG's went on dry. RTV is on exhaust gaskets.

#4 ystrdyisgone


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Posted 05 July 2014 - 12:39 AM

5. Mystery pieces
              Anybody know where these go and if they are important??
The piece on the left looks like the rubber piece that goes into the O2 sensor plug to make it watertight. The middle piece should be the piece that goes on the backside of the alternator bolt. The right piece is simply a wire holder, not sure where it might go though

#5 heartless


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Posted 05 July 2014 - 07:10 AM

the sound is from the exhaust leaks - get new exhaust gaskets, clean the mating surfaces and put them in dry - never use RTV on exhaust parts. Also, if the studs came out fo the block when you dropped the exhaust, you really should replace them - it is VERY difficult to get them tight enough again to prevent leaks when they do that. Speaking from experience here - blew out 2 exhaust gaskets on the same side on my car due to this. Go to the "HELP" section of your local auto parts store and find exhaust studs (and nuts) for I believe Nissan - they should have the correct thread pitch to fit the block.


the right most bracket does look like the one that holds the O2 sensor wires out of the way, should be mounted on one of the passenger side tranny bolts. Not super important


the middle bracket is for the alternator - goes on the back of the long bolt the alternator pivots on - nut facing the intake. Important.


Did you pull the wires out of the O2 sensor itself? or out of the plug? If out of the sensor itself, or the sensor side of the plug, you may be further ahead by just replacing it.


Coolant temp issue - did you replace the thermostat? If so, if you used other than an OEM Subaru T-stat it will cause issues.

T-stat aside, your description sounds very much like air trapped in the system. When refilling, did you fill the block through the upper radiator hose? if not, you almost certainly have air in the system.

Might also be a good time to replace the radiator hoses. if they are soft/mushy, definitely replace.

#6 Fairtax4me



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Posted 05 July 2014 - 10:50 AM

How bad did it overheat before you changed the head gaskets?
The DOHC blocks are famous for eating rod bearings after overheating.

Hard to tell from the videos, but to me the knock sounds too deep to be an exhaust leak.
Did you make sure all of the buckets and shims on the valves went back on the valves they came from?

#7 johnceggleston


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Posted 05 July 2014 - 11:36 AM

the sound is from the exhaust leaks - get new exhaust gaskets, clean the mating surfaces and put them in dry

did you reconnect the EGR pipe to the head and the manifold ?this will create an exhaust leak.

but it is probably the RTV.

Edited by johnceggleston, 05 July 2014 - 11:38 AM.

#8 Farewelltoernest



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Posted 05 July 2014 - 04:07 PM

Thank you guys so much for replying!

I suppose I'd better get that alternator bracket back on stat. Any idea if that's what is causing my battery light issue? Probably not, but worth asking.

From what I can tell the studs on the block are just as they were before dropping the exhaust.

EGR pipe is connected, yes.

O2 wires came out of the plug, not the sensor itself. Just need to know the order to plug 'em back in.

The valve shims were not changed or removed. Buckets were labeled before removing, and out back in the heads in order.

The car has a lot of miles, and made the sound before, it was just MUCH quieter than it is now.

Same thermostat. Weird thing- I unplugged the out of order wires from the o2 plug- and it's no longer acting erratically. I am still planning to remove the air from the cooling system though.

Car never overheated with the old HG's. Just some minor fluid mix.

I'll bump the thread when I change out exhaust gaskets and let you guys know how it went. I also want to take a look at the intake and see if it's the same story there.

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