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2nd HG Failure in 3 months!!! is it my AC?


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Short story.

 

Bought with know HG Problem

 

97 OBW

2.5L AT

100K miles

 

 

Complete engine rebuild with non OEM head gaskets lasted 10k miles saw the bubbles in the coolant resivor shortly after I started using the Air Conditioner blamed it on the cheap HG's.

 

Just finished replacing the HG's with OEM gaskets, (Installed to exacty to specs in haynes manual) Checked head's and block both were straight. Heads also passed pressure test so I dont think they are cracked.

 

Ran the engine 500 miles (no AC) and everything looked good, my coolant level was staying constant and no bubbles.

 

Got brave and turned the AC on for 50 mile hi-way trip. After the trip coolant res was full and hose was bubbling worse than i had ever seen it.

 

I dont see how the extra power the AC requires is "The straw that brakes the cammels back" on the gaskets.

 

It must be soemthing else that i am not seeing.

 

I would appreciate any hellp you can offer becasue I dont see any reason to try and fix this engine again unless I can identify what is actualy causing my problems.

 

Thanks

 

Ben

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are you sure it's the headgaskets? is it actually overheating, can you see the gauge saying it's overheating?

 

sounds like maybe the radiator is partially plugged. how much stop leak was used in this thing in the past? the a/c causes the air in front of the radiator to be heated as it goes through the condensor so the air flowing through the radiator is much hotter than with the a/c off. maybe the radiator is clogged, not enough to run hot normally but when the a/c is on it puts it over the top.

 

are your fans turning on when it gets hot or the a/c is turned on?

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When I replaced the head gasket's 500 miles ago I could visably see where the cheap gasket had failed.

 

I am not for sure that it is a HG this time but I dont know what else would make bubbles come out in my overflow tank imediatly after the car is shut off.

 

Both fans are working properly I have checked that.

 

The car has not yet overheated since the last HG job. But i am sure that it is coming.

 

I checked the radiator during the last HG job and it appears to be good. Water flowed through it with no problem and no foriegn material was found.

 

 

Thanks for your help, because obviously I need all that I can get.

 

Ben

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I'd be curious to see if this failure is the same as the last. If so there should be a common flaw to cause the failure that you haven't figured on.

 

Otherwise if the failure looks like a different area or side, I would not ask you to buy me a lottery ticket!

:lol:

 

Sorry for your troubles, hope you're able to get a diagnosis and correct it.

:-\

 

As an after thought: have you replaced the water pump and also check the drive belt tension? I know that these are obvious...but you know how that goes.

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what kind of bubbles? a HG will push water out in huge amounts and fill the resivoir. Run the car with the cap off and if you still bubbles then something bad is happening. There are the big bubbles from a blown hg, or the little bubbles from a worn waterpump impeller.

Check to make sure there is no air bubble in the cooling system.

Pull the plugs, one should be cleaner then the others if you are burning water.

Check the hoses to make sure they are tight.

Replace the radiator cap.

Have the system pressure tested.

Test for hydrocarbons

 

Do you have heat?

 

nipper

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The following new OEM parts were intstalled during my second HG job.

 

Water Pump

T-Stat

Radiator Cap

Upper Hose

Lower Hose

 

Timing belt is new and tight as well.

 

System pressure checks good with my Snap-On tetster.

 

I dont really want to spend the money to check for hydro-carbons, i am allready starting to get the residue in my overflow tank and some crud on top of the water.

 

Do you think I should try again or just buy a used 2.2 and drop it in?

 

I dont have it here in front of me but the head bolt procedure in the haynes manual seems a little odd to me.

Basicaly when it is all said and done the outer four bolts have 75lbs tourque and the two middle ones only have 22lbs (if i remeber correctly)

 

Is that the procedure that you guys use?

 

Do you think reusing the head bolts for the 3rd time had something to do with it?

 

For the gasket to fail in the first 500 miles something is major is wrong and I cant figure out what it is.

 

Thanks again.

 

Ben

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not so much the headbolts, but maybe there is an outside chance the threads are tired, im a bit stumped. it passed a leakdown test. The bolts are steel, threads are in aluminum. You may want to recheck the torques.

Hydrocarbon test is available at autozone. The extra heat load from the AC usually means a clogged radiator.

Run cold water through the raditor and make sure the radiator is the same temp all the way across. When you drain out the cooling system to do this try to run the fluid through a filter of some kind, see if its rust your seeing or oil in the fluid. Its possible the radiator is gummed up from the 1st time the HG blew and was never properly cleaned.

Check all the other possible water passages.

 

without seeing the engine, i hate to say it, but there comes a time to surrender.

 

nipper

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Nipper,

 

Thanks for all of your help on this subject.

 

The engine has not yet over heated since this last head gasket job. I have watched the temp guage religously and it stays right were it should.

 

When I hook up my Scan Tool it tells me the temp is staying between 190 and 202. I know the temp guage works becasue my last HG issue casued a couple slight overheats and the guage worked then.

 

Unless the the overheating is localized in the combustion chamber area only my cooling system is working properly.

 

Thats why I cannot find a reason why I can blame the cooling system or my AC for the gasket failures.

 

Thanks

 

For all of your help.

 

I think I am going to buy a USED 2.2 and rid my self of this nightmare.

 

Any opinions on a good place to buy a used 2.2L engine.

 

Thanks

 

Ben

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i hate that i cant be there in person, il'd hate you to replace the engine nad have the same problem.

Two choices, im wondering if the radiator is clogged and you cant tell, or its a timing issue.

if i was you, i would spend the mnoney to have a emchanic look at it. That doesnt mean he has to fix it.

 

nipper

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like nipper said you'd hate to go through an engine swap and find out it's still doing it. (been there done that on much smaller projects, and even then it's annoying and you're still scratching your head later).

 

of course if you get to the point with hands up in the air and nowhere else to look you might be ready to do it. been there too!

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Thanks for all of your help guys.

 

Having a mechanic look at it is a little harder than it sounds. I live in rural Nebraska and the closest "stealership" is over 250 miles away and they sell 5 different brands including Subaru so I am not sure how good their service department know Subarus. As far as local mechanics go most dont want to work on any thing past a 350 chevy and they run and hide at the thought of an import. I found one shop that would look at it but he told me he had not worked on a subaru in over 10 years....... Another shop that i know of had a late 90's outback with overheating problems in and out for four months before I told my buddy to tell them to search Head Gaskets on this site. (I have not heard if they figured it out)

 

I am sure that I could take the car to the denver area (300 miles) and find a very good mechanic but by the time i pay for all that I could have a 2.2 installed.

 

Once again thanks.

 

Ben

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