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Are my bad Cylinder Valves related to the Head Gasket?

I have a 1998 Subaru Forester and got a $2,400 Head Gasket repair only a 1,000 miles ago. When I got the repair they said my Cylinder Valves checked out and were good. Everything was going well until I attempted a drive last weekend in which case my check engine light turned out and my car starting shaking. My head gasket repair is covered up to 10,000 miles and was wondering if anyone thinks this valve repair is related. The repair shop says no but it seems suspicious because usually valves don’t blow until around 200,000 miles. Mine has 118,000.

Here is the estimate I was given:

Doing Valve Job on #1 & #3 Cylinder
Labor for R & R Head (Reg $630) $315
Headgasket (Reg $ 46) $0
Intake Gasket $14
Antifreeze $12
Misc $40
________
$381
Headwork $250-300

Estimate $631-681

Valve Job on all 4 cylinders
Labor R & R Motor/Heads (reg $1170) $450
Headgasket (reg $92) $00
Intake Gasket $14
Antifreeze $12
Misc $40
__________
$516
$45-500

Estimate $966-1016

Let me know what you think. Thanks.

Your engine is an interference engine. That means that of the valves don;t stay in time with the crankshaft, the pistons will bang into the valves and bend their stems…or worse.

What I think happened is that either your valves were mistimed when the head gaskets were replaced or the timing belt (yours has one) has jumped a sprocket tooth due to a weak tensioner, a worn out belt, or oil on the timing belt system (which can weaken the belt, lube it, and allow it to jump).

What I can’t figure out is why the belt and related parts weren’t changed when the headgasket was done. I also don;t understand why I don;t see these parts on the new estimate.

OK4450, you’re a Subie expert. Am I incorrect in my understanding that this is a belted engine?

It has a timing belt. On the surface it’s pretty coincidental but there’s a lot of unknowns from where I sit. Some of those are:

Compression test before the head gasket repair and for the valve diagnosis along with the readings.
Whether the head gasket replacement was due to weepage or severe overheating and if overheating how long did it go on.
Whether valve lash was ever checked and adjusted if necessary.
How they determined the valves were good when the original work was performed.
Whether the timing belt was aligned properly as mentioned by mountainbike.

I could see this thing going in a number of directions so it’s difficult to say for sure what the cause is.
From the get-go, a compression test should be performed on all cylinders in the event of a head gasket fault. This would detect any piston ring or valve problem on cylinders not affected by a head gasket breach.

I don’t know whether they inspected valve lash or not (likely not) but that’s something that should be done every 30k miles.
My personal opinion is that valve lash should be inspected and adjusted with every head gasket job.

Just my opinion, but if I were doing the job on a 15 year old Subaru with 118k miles and especially with a head gasket fault I would do a complete valve job and surface the heads at that time while replacing the valve seals. If it was a warranty procedure or a low miles engine then the valve job might be given a pass but only in that situation.

It’s also unknown how the valve job labor cost is figured. If the amount quoted (250-300) is for grinding the valves and seats only that seems high to me unless they do their own valve work (not likely), the auto machine is high, or they’ve adding a substantial markup to the auto machine shop charge.
Around here it’s 5 dollars per hole, meaning each valve/valve seat. That means even on a 16 valve engine it’s only 80 dollars for the valve job. Surfacing heads, if needed, are 35 each. It could be the area where you live is priced much higher than than where I live.

That’s pretty lengthy and I hope something useful can be gleaned from it. I apologize for not being more precise.

After 1000 miles from a head gasket repair you now have valve problems? Very suspicious! The estimate seems to indicate the shop did something wrong on the original job since they are giving you some relief on some of the labor charges. I think they messed up the job and now you need to negotiate a deal that is fair to you and the shop.

Thanks to everyone for responding. Here is a little more information.

So this is what was said in the email from the mechanic, “Misfire #1 cylinder, found 70 pds compression, leak down test showed exhaust valve leak.”

When I blew my head gasket a little while back it was probably driven about 100 miles before the operation was done. It was due to overheating.

Does this change anything?

I’m going to email them some of this information and see what they say. Their communication has been slower than usual with this issue which also draws my attention that something is off.

The 70 PSI of compression is bad and in most cases it traces back to an exhaust valve problem but this is still a bit murky to me.

If the head gasket failure caused engine coolant to enter the combustion chamber then that could certainly have created a problem because hot engine coolant is very corrosive to exhaust valves and seats. This should have been checked and noticed while the heads were off.

If the problem is caused by tight valve lash on that one cylinder then one of 2 things could have happened.
It could be a sheer fluke that the valve tightened up after being borderline for a long time or it could be that the valve lash tightened up due to an overheated engine; if that was the case during the head gasket failure.

Everyone has their own methodogy but considering that the valve lash really should be checked and inspected every 30k miles there is no way I would do a head gasket job without checking valve lash.
At this point I don’t want to fault the shop because as I said, there’s still some haze to this.

As ok4450 keeps saying, its really hard to know for certain exactly what is going on or where the fault can be laid - or the unfortunate “cause” if there is no human fault.

But its starting to sound to me like they just pulled the head off and slapped it back on and didn’t check anything about the head or valves. I especially find head leak-related valve damage to be plausible alongside the guess that nothing was actually checked.

What kind of a shop are we talking about? Its not a big, corporate chain “auto care” type of operation is it?

I have always been told that if you are going to do a job, do it right the first time. This means if you do a head gasket, get the head re-done. Its usually about $150-$250 for a typical 4-cyl, yours maybe more as you have two heads… However spending that little bit then would have prevented these issues now. I am not blaiming you BTW, I am blameing you mechanic. It seems like he cheaped out and cost you a lot of extra money.