86 Turbo XT blown head gasket?

[esechter]

Hey all,

 

I have an 86 Turbo XT (EA82) that's had some serious power issues lately. The engine seems like not all cylinders are firing. The car pulses/shakes back and forth at idle, and almost seems like it's going to backfire. It struggles to start from a stop or climb even the slightest of hills - I often find that it doesn't start really moving till the turbo kicks in or I apply wide open throttle. However, it's fine on flat roads above 35 mph.

 

I checked the timing with a timing light - it's apparently correct. I checked the spark plugs, they were all sparking, but I decided to replace them anyways. I replaced the cap and rotor. I replaced the O2 sensor. I ran a compression test - everything tested consistently. I found that the fuel injector connectors were corroded, so I've ordered new connectors that I will wire in. I figured the culprit was a bad connection and that a cylinder wasn't getting any fuel. I also ran seafoam through it in case an injector was clogged. When it was smoking from the seafoam, I noticed some coming up out of the engine around the turbo. I don't think it's related, but there's an exhaust leak somewhere.

 

Today I took off the PCV valve on passenger side (the side that seems to be running funny) and it stank of fuel. The valve on the other side didn't. Do I actually have a blown head gasket?

Edited March 13, 2011 by esechter

[idosubaru]

doesn't sound like head gaskets and if the compression tested fine then you're probably okay. normally these things have bad compression numbers if the head gaskets are blown. what values did you get? but of course an EA82T with a blown headgasket sounds familiar.

 

you replaced plugs, cap, and rotor - replace your wires too. i wouldn't do anything until you replace those as well.

 

any check engine light?

 

CTS gets corroded terminals and causes issues similar to this, though that's more common on the XT6's.

 

There's a few other options but those are two common issues i can think of.

[MilesFox]

try replacing the engine temp sensor. typical symptoms are starting up fine, but once warm, runs crappy and hard to start. Typically the connector corrodes.

[idosubaru]

try replacing the engine temp sensor. typical symptoms are starting up fine, but once warm, runs crappy and hard to start. Typically the connector corrodes.

Just so he doesn't get confused, that's the CTS I mentioned. Green nastiness on the connector metal spades/slots may mean you're onto something.

[esechter]

Thanks for the replies!

 

I forgot to mention I did the spark plug wires.

 

All of the connectors on the car have the green corrosion. If it's not an injector connector, what other connections/sensors should I be looking at? Some candidates I was wondering about: TPS, Crank position sensor, the engine temp which you guys mentioned, others?

 

The check engine light is not on.

 

The car sounds wrong as soon as it starts - it runs with a noticeable thump-thump-thump (no metallic sound though) and it stays that way warm or cold, driving or idling. The power is low at low speeds and improves at higher speeds, but even at highway speed it isn't right - the turbo immediately kicks in when you want to accelerate.

 

Compression test results:

Cylinder 1: 108

Cylinder 3: 113

Cylinder 2: 112

Cylinder 4: 120

 

And it's probably worth mentioning that this is my boyfriend's car, so you can address me as "she"

[Twitch de la Brat]

Ok, what brand of spark plug wires are you using and what brand of spark

plugs are you using?

 

I've seen Napa and Borg Warner wires spark through the boots on Subarus

(and a Mazda).

I recommend only Subaru, Bosch (if you can get them) or NGK wires.

 

Your spark plugs might be the issue as well.

I only run Bosch Platinum +2's in my cars, but others highly recommend NGK's.

If you're using Autolite or Champion spark plugs, that may be your problem.

 

Good job on running the seafoam for a fuel system cleanup, it'll help a lot.

Instead of ordering in new connectors for the fuel injectors, I recommend just

cleaning them, unless they're obviously broken, then new ones would be in

order.

 

Listen to Grossgary and MilesFox, they've both been around the block quite a

few more times than me and are good at internet diagnosing cars.

Plus Grossgary has probably owned at least one of each year XT ever made,

turbo, NA, and the 6 cylinder engine

 

Twitch

 

PS: Have you tried pulling spark plug wires one by one to determine if you

have a dead cylinder?

Or watched the engine in the dark while it was idling?

If you see an occasional spark by a wire, that means you're getting spark loss

on a wire.

 

PPS: For either of your safety, I highly recommend NOT pulling wires while the

engine is running, because if there is a bad wire you will get one HELL of a

shock, don't ask me how I know.

Edited March 13, 2011 by Twitch de la Brat
More details

[misledxcracker]

PPS: For either of your safety, I highly recommend NOT pulling wires while the engine is running, because if there is a bad wire you will get one HELL of a shock, don't ask me how I know.

 

Yeah, it hurts like hell! I managed to do it twice in a row

 

Is the exhaust in good shape? I get a "thump-thump-thump" noise starting up my non-turbo XT, my exhaust isn't in good shape :-\ anyhow, something to check into, for what it's worth.

 

I'm not that good with turbo models, however I do know that the sensors can go out of whack slightly, causing issues and still not throw a Check Engine light. It would be a good idea to grab the FSM off the forum (wherever it is) get a multimeter and test all of the sensors, while cleaning the connectors at the same time.

[idosubaru]

did this car sit for an extended length of time?

are you using any fluids or not putting enough miles on it to tell?

 

okay "she", gotcha. do you know offhand the compression numbers for the turbos?

 

the 108 and 120 is "within range" of one another since i think they say 20% but doesn't sound great.

 

was the throttle propped open and were all spark plugs removed for compression and a really good charge on the battery? each of those will reduce compression numbers or make them inconsistent sometimes.

 

we need someone with a little more turbo experience - what problems would a hosed turbo cause?

[NorthWet]

My first thoughts would be the usual: Corroded CTS connection (check it, double check it, and then do GG's fix anyway ), and high-tension system.

 

In my experiecnes, turbo models seem to be finicky about their high-tension systems, possibly due to poor management of A/F ratio causing variations in required spark-voltage. I have had bizarre issues with EA82Ts having flat spots in different portions of the its RPM range, curable with new plugs/cap rotor. Sounds like you already took care of the spark plug wires.

 

If the turbo itself failed I wouldn't expect much other than evenly lacking power, maybe top-end power dropping off due to exhaust restriction. The uppipe to the turbo is prone to cracking at the turbo-inlet flange: This tends to make a hissing/whirring noise at idle but quiets as revs increase. But this tends to delay the onset of boost, plus decreasing it to low levels rather than poor running at low RPM and ok running on boost. The smoke near the turbo during seafoaming may be coming from a broken uppipe flange, or just some other exhaust gasket.

 

How did you "check the timing"? Did you connect the green connectors near the ECU in the trunk, set the timing to 20dBTDC, and then disconnect the green connectors.

[Ardent_Penguin]

Hi all, the car currently in discussion is mine. Isn't my girlfriend awesome for helping me out? Y'all have asked a lot of questions, so this may be a bit long:

 

The car has not sat for more than a month since 2006. It sat for the last 6 months of 2006 while I rebuilt the front end (it has an 89 XT6 bumper/frame and radiator frame). At the end of that, it got new timing belts, MSD ignition coil, cap, rotor, wires, plugs (iridium), brakes, wheel bearings, C/V boots, radiator (two-row radiator), aftermarket oil cooler and transmission cooler, and new exhaust. Ran great till early last year, then it got a new battery and alternator. Ran well for the rest of last year.

 

I think I've put less than 20k miles on it since the start of 2007. I replaced the spark plugs, wires, cap, rotor when it began having problems, and there was no improvement.

 

I don't recall if I connected the diagnostic connectors for the timing check. I don't have time today, but I could do the timing again tomorrow. I believe I was also told to disconnect the vacuum advance on the distributor while checking timing.

 

The compression test was done with spark plugs out, fuel disconnected and the person operating the key also pressed the accelerator pedal all the way down, thus holding the throttle open. Around the same time, my car was needing a jump start, so a low battery may have impacted the test... but I think we double-checked all the cylinders.

 

Girlfriend did the spark wire pull test on the engine last night while I was at work. She said it had the same effect on each cylinder.

 

I managed to find Bosch EV1 connectors for super cheap, so I ordered enough to do all the fuel injectors and both sensors that use them (I don't mind a few minutes of soldering). Today I replaced the connector on the CTS(I think it's the CTS? It's the one on the engine, where the top coolant hose connects) and that had no effect.

 

There is also a temp(?) sensor on the radiator: when I disconnect this one, the engine doesn't run any smoother, and it revs up to 1600 or so at idle. I cleaned the contacts on that one, and re-attached it.

 

And finally, the electrostatically controlled radiator fan turns on with the ignition, even if the engine is cold (like below freezing outside).

 

I think that's all.

[naru]

Those corroded connectors can`t be good.Fix/clean as many as you can.

Pay attention to the airflow meter connector.

 

Exhaust leaks before the turbo kills power in turbo cars,but,don`t usually affect idle.Not uncommon for the up pipe to have holes under the heat shields.Holes here can give a false o2 sensor reading.Try it w/the O2 sensor unplugged.

 

Try it w/the CTS unplugged too.

 

After confirming correct ignition timing,I would put a voltmeter on the O2 sensor to see if it is rich/lean.Might be just a vacuum leak.

 

Inspect the rubber intake piping for cracks etc.

 

New fuel filter is always a good idea,but, probably not your problem.

Try to blow thru the old one.

 

Distributor shaft have much sideplay?

Vacuum diaphragm good?

 

AFAIK,if you have defrost selected,fan will run regardless of temp.

[Ardent_Penguin]

I tested the O2 sensor a month or two ago, and the reading was alternating, so I think the O2 feedback was working.

 

There wasn't a noticable difference with the CTS unplugged, so that may be the problem: bad CTS.

 

Fuel filter got replaced when I did the O2 sensor, as part of the diagnostics.

 

I haven't checked the vacuum system, as it is kinda scary on this car. It looks like a tentacled beast wrapped around the engine.

 

Car has just under 140k miles, spent most of its life in warm climates, now lives in the pacific northwest: land of salty roads in the winter, and lots of rain at other times. Poor car.

[esechter]

Just an update to say that the CTS and its connector were replaced with no change. Have yet to double-check timing or replace the fuel injector connectors. We'll post updates when we get these done to confirm whether they are the source of the problem.