Subaru waped heads


#1

I posted a question about warped cylinder heads a few days ago. The Subaru dealer has been great and they are repairing the vehichle under warranty. My new question is how did the heads warp so much? More than 4 times the allowable limit .009. I never had an overheating problem and I followed the manufaturers maintenance guide to the letter. How can I prevent this from happening again?


#2

Not having the benefit of the info in the previous thread, I can only guess that a previous owner DID have overheating problems.(or did you buy the car new?)


#3

I remember the previous thread but do not know if you bought the vehicle new or used. If “new”, was it a dealer demo or something?

The maximum allowable is .002 before surfacing is needed so .009 is huge no doubt about that.


#4

Yes, the car was brand new, not even 100 miles. For those that haven’t seen the previous thread, it is a 2005 impreza 2.5L non-turbo with just under 60,000mi. One head was .009 the other was .004.


#5

A 100 miles means that the car was a demo, dealer transfer, etc. more than likely. This could be determined for sure by contacting Subaru of America and finding out when the “put into service date” was. A “new” car has an into service date on the date you purchase it. If the service date was some weeks, or even a month, before purchase then this means demo use, etc.

I bring this up because sometimes a demo vehicle or dealer transfer can literally get the crap driven out of it. We had one transfer Subaru brought to us one time and the driver absolutely cooked the turbocharger in it in less than 500 miles. Another salesman took a demo Fiat Spyder out one weekend and essentially totalled the car out without wrecking it; seriously. Two bent wheels, broken windshield, blown transmission, 2 bald tires, caved in RF fender, rattling engine and half a dozen other things. This car did not even have 300 miles on it yet and was relegated to being a parts source to keep others running.

Assuming it was not abused along the line before you bought it determining the cause may be near impossible to determine.
A possibility of someone at the factory not properly torquing head bolts or whatever; who knows. The .004 is bad enough but could possibly be understandable since it is possible for a cylinder head to curl up a bit when the head bolts are removed. That .009 head really raises the red flags. I’ve seen many overheated ones that were not that bad and certainly don’t see any normal curling as contributing to that much warp.
Hope some of this helps anyway.


#6

How does one “cook” a turbocharger by driving a car. In the old days one was supposed to idle the car for a period to make sure the turbo was cooled down. This is certainly too much to ask of the average driver.


#7

I have no idea how the delivery guy roasted this one. He left San Antonio just before 6 in the morning and arrived at our dealership before 1 P.M. This was a total of about 450 miles, 3 large metro areas to cross, and stopping to grab some fast food. By doing the math it appeared he had it hammered down pretty good.

The car was dropped off and the guy was instantly given a ride to the airport to catch a flight back. When the detail guys went out later to bring the vehicle inside for final cleaning before delivery to the customer a note was found on the seat stating “the car runs pretty sick”.
I had to change the turbocharger unit under warranty and had to remove the entire thing with a cutting torch. It was that bad and no way would any of the nuts/bolts come loose even with an air wrench, and this vehicle had a total mileage equal to only the amount driven from SA to OKC + about 10.


#8

That Fiat Spyder bit is hilarious! Did anything happen to the salesman for that little escapade?


#9

I assume the salesman went to work elsewhere. He took off on Fri. evening in it and based on the evidence (including an empty Vodka bottle in the floor) it appears he decided to go to Tulsa in it and party down. This led to him apparently getting stuck up to the taillights in mud somewhere and no doubt being intoxicated to oblivion, chose to try and spin his way out of trouble.

Failing that, he left the car where it was sitting, called in the next day to give his notice along with the car’s location, and never came back for any pay that was due. Imagine that!
The car was towed back from Tulsa (100 miles roughly) and it was pretty darned sad to see a brand new red Spyder in that condition. Close to 20 grand worth of car flushed in one evening!


#10

OK, what happened to the ‘turbo cooker’?


#11

Ouch. I hope his night in Tulsa was worth it!


#12

You can’t prevent Subaru heads from warping. They have a mind of their own, or is that a no-mind?


#13

My guess is a defective turbo, low oil level(esp if oil cooled), oil line or coolant line if the car had one.

A turbo car can run at top speed (mostly in boost) all day long if everything is working properly.


#14

The customer was told of the cooked turbo problem and wanted the vehicle anyway once a repair was completed. He was given an extra discount on the vehicle and a free extended warranty (factory authorized) because the car was a transfer from the regional office and a regional office employee was the one who did it. Maybe an ex-employee after this.

I replaced the entire turbocharger unit along with all of the hoses, etc. (and a bunch of nuts/bolts that had to be cut) and the car was fine. There was some concern before the turbo replacement that the engine itself may have suffered a bit but a careful examination, along with keeping the car and driving it around for a few days, showed no problems.