nipper

Sooby's that are OBDII need an OE O2 sensor for the front one. On an OBDI I havent heard any complaints about using universal ones, just use a brand name.

Well a failed sooby HG wont lead to overheating immediatly, but a cooling system failure (broken hose no coolant) will lead to failed HG on almost any aluminum cylinder head engine. nipper

Youll see it on an OBDII readout, but yes the gauges are numb in the normal range, otherwise they will get alot of people saying thier temp gauges are moving all over the place. And since the majority of people are stupid, it ties up shops (80's gauges were very reactive, and this is the lesson that OE's learned... that customers can be idiots) As you start getting out of the normal range they are more accurate. nipper

heheh knock senser can be from anywhere

You mean water injection?

Your going to hate me. Get one from OE and do it again. Come summer you will be running hot. there ios a vast differnce between OE and stant t-stats. nipper

Usually that stuff is very expensive scented lysol. nipper

PS. You can also add in open deck vs closed deck design (and even hybrid deck....confused yet ?). To me i know how it fails in subarus, i just dont know what kicks off the entire process. Since it is an open deck, the HG is not fully supported. Imagine trying to pry against a hollow core door vs a solid door. the solid door wont give, or will take a very long time and alot of work. The hollow door will yield fairly quickly. Since they were commited to hollow core doors, they went with a 3 peice door (HG) where the outer skins were steel. Now it is as strong as the solid core door (still with me?). Now since there is not a 100% failure rate (i'm looking at you Dodge Neon) the question is what sets off the failure. That I dont know, and i dont know if anyone will ever truly have an answer, but you can design around all the known causes and beef them up, and erradicate the unknown cause. Maybe it is just one bad tank of gas that causes ping, maybe its a bad batch of HG's, maybe it was just the monday crew in japan hungover. nipper

Nope. HG's are extreemly complicated parts and no one issue kills a sooby HG. u look at the history of the automotive industry during this time, emissions went from OBDI to OBDII with tighter specs. There was a very short time to adapt and desighn to the new standard. Everyone had head gasket issues during this time. The materials at the time were at the edge of what they can do (which is why the failure rate industry wide was from 100% to 15% and everything inbetween depending upon how cheap the HG's were made to begin with). Also some things need real world testing. Even lab testing takes time for analysis and to come up with a correction for the failure. When a critical part fails a test, the test starts over. Sometimes the tests themselves, while consistant, do not reflect real world conditions, and sometimes they just can't (like reproducing 150,000 miles of city driving). Failure starts in the combustion chamber, where spot temps are a few 1000 degres and combustion pressures can be in the 15,000-18,000 psi or more range. This is all precisly controlled by the computer, except when you get knock. Knock is one of the biggets detriments to HG (assuming the engine doesnt already have a design weakness) Subarus tend to run fairly consistantly at 175- 205 depending upon the outside air temp and load. ine to market (computers We expect alot of our cars, and sometimes, we just have to be living labratories. It can take up to 10 years to bring a new engine to market, though computers (for development) have gotten faster and have reduced that number to 6, unless something in the market changes, then it is back to square 1 again. nipper

Lets get that knock sensor replaced first and do a good old fashioned tune-up. If the O2 sensor has more then 80K on it be prepared to replace it, but wait untill you get a few tanks of gas in the car to see if that knock sensor was the issue or not. nipper

Drop the blower motor and see if there is anything dead in it. wear a dust mask. nipper

Piston slap. Nothing to worry about really unless it never goes away. nipper

I'm going with a leak too. So far the H-6 water pumps seem bullet proof, but then again a idler letting go at speed can seem like a bullet if your in its way. You may have nicked something. nipper

Nope just wear ear protection.

Still need the codes or we can guess all day. nipper

People people people, when you skimp on the timing belt parts they will come back to haunt you. This is like the 5th post on three different boards I have had to answer, all about the same mileage where people did not replace the idler or tensioner (which subaru highly recomends gets replaced with the TB. Before we start throwing money at sensors we need to read the engine codes. Feel free to throw all your money you want at it, but thats is not my way of doing things. 1st we need codes. 2nd we need to insepct the idler and tendioner and engine timing to make sure it is all good. Rough running and then no running is not a good thing. Sensor possabilities - Engine temp (but car would run when it was warm outside with no isseus) or smoke at start up. Crank sensor, no start at all OR a fire then a stall, then a few no starts, then be fine.

What parts were changed when the timing belt was done? We need to know the codes. There arent too many things that will keep a subaru from running.

That CEL is not there for decoration it really sholdnt be ignored without investigating it. How many miles on this car. When was the last time it had a tuneup When was the last time the timing belt was changed? nipper

My outlook on OE parts. If the original part lasted 106,000 or more miles, I would go with OE again. Thats just me. Also look at the on line suppliers to see if the costs are competative to aftermarket. I will say I have yet to hear of an aftermarket WP going bad prematurely, in any make or model car. Seals (if you are smart) should be OE. T-stat (what the heck your there) should be OE. DO the PCV valve just because. nipper

I dont know why the dealer is charging so much for this job aside from the fact they dont want to do it. Even by subaru rates and book time it is not a 1000.00 job. nipper

That first shop is a moron, and the second one a rip off. www.endwrench.com in the archives under engine in the timing belt article specifically recomneds replacing bothe parts and even states they arent designed to last past 106,000 miles. Bring the car home and do it yourself. The most I ever paid for a TB change (including seals and water pump) was 650.00. nipper

I am going with a circuit breaker. nipper

But i wasn't going to tell him that. If the O2 senser is over 80K it can be due, and the farther away from that number the more likely it is. You can do all sorts of testing, but when it is obvious it is what it is, then just replace it. nipper

Better question, how long do you want the car to last and how much money do you want to piss away? You can not reuse head gaskets, as they are a compression gasket. They are designed to be deformed when the bolts are torqued. What are you calling low comprsssion? I would do an engine swap, as doing a low budget rebuild will most likley come back to bite you in the wallet relativly quickly. nipper

I had it happen on a datsun once. nipper