1998 V90 Want to repair/replace cylinder head.. am I insane?

[crosscut123]

I recently acquired a 1998 V90 with 125 K miles on it. It has the 2.92L (3L?) L6, 24 valve non-turbo gas engine. Owner's manual says that cam belt was replaced at 70K. Engine has a miss that I have diagnosed means it probably has a burnt valve. 0 psi in #3 cylinder, 190-195psi in others. Oil injected into cylinder #3 doesn't change psi. No blow-by to speak of. I assume I will have to remove the head and replace one or more exhaust valves. Is this something an enlightened amateur should attempt? I have rebuilt several traditional engines in the past, but nothing like this one. I'm waiting for a workshop manual to come, but in the meantime, what little information I am gleaning from hints on the web make me think that volvo has made repairs harder than they need to be, with numerous ridiculously expensive special tools and a reticence from dealers for sharing any information. I also read that volvo doesn't make replacement valve guides for this engine anymore and requires repairs to be made with factory-rebuilt heads. Since I'm assuming that I might need to replace a valve guide or two, what's that mean...just buy a replacement head and throw the old one out? When I buy a rebuilt head, am I likely to get a complete head, or just the core...and I have to replace the valves and cams, and ?? Anyway, some advice from experienced hands would be appreciated before I go past the point of no return on this car. Thanks in advance!!

[volvoaddict007]

Compression on the rest is great! Sounds like a valve is stuck open for whatever reason.

I am suspecting your problem will be determined once a valve cover comes off.

Since you are willing to do a head replacement this is the first place I would look.

I'm betting on a dropped valve, collapsed ( broken )valve spring or (askew or broken ) rocker arm although I am unfamiliar with this motor.

Either of these scenarios may require a cam R & R at the worst.

Especially since this is a rear wheel drive vehicle, instead of going through the headache of a head replacement ( if needed ), I would tend to go to VOLVO and SAAB Auto Dismantlers in Sacramento, CA or another reputable VOLVO salvager and buy an entire used motor. V&SD will gaurantee a motor 90 days or lifetime for an additional charge as well as asking for your vin# to assure the proper replacement. They also will tell you mileage and compression on the prospective motor. A motor delivered should cost about $900. Do the timing belt, water pump, rear and main seals while you're in there

I've aways felt that heads and blocks together from the factory are your best bet.

They could have a motor with fewer miles that adds value to your car at the same time. That car all cream puffy should bring at least $5000 - $6000 on the used market.

va007

[billofdurham]

Major problems with taking off the head and replacing it include:

They invariably have to be skimmed.

You need all new cylinder head bolts at a mega-price.

Valve guides are still listed but, apparently, in short supply in the UK so I would assume the same in the US.

va007's suggestion has great merit.

Bill.

[volvoaddict007]

va007's suggestion has great merit.

Bill.

Why thank you O Great One.

I'd put a short piece of garden hose on that valve cover over #3 ( like a stethescope ) and listen for something unusual. I overrevved a Saturn motor once and the dealership claimed nothing was wrong with it when there was an obvious miss. I had that particular valve cover off in 5 minutes and there was a rocker arm that had just popped off and was laying there. I popped it back on with a screwdriver and a pair of vise grips and was good to go.

Hey Bill, I'm unfamiliar with a V90 valve train but isn't there some sort of retaining clip ( a C-clip ) that holds those valves on and maybe someone at the factory...or for whatever reason, it broke or fell off?

That's my best guess.

OK crosscut, now I'm curious. Get that daggum valve cover off o' there and report back

va007