hello again all!

haven't posted/lurked around here much since replacing my heater core:
https://volvoforums.com/forum/volvo-v70-13/link-1998-volvo-v70-heater-core-replacement-w-pics-21960/

1998 v70 standard, 174K

so i was driving from raleigh to charlotte (from charleston, sc) this past thursday, 7/1. in the middle of the trip, my check engine light started blinking and the car suddenly felt as if it was losing power up hills and around 3K rpm. as it was the middle of the night and my phone was about to die, i finished the last hour of the trip to my friends house.

i woke up the next morning, replaced the spark plugs and spark plug cables with no luck. took the car to the local volvo dealership, who told me it was likely the rotor and distributor cap. another $270 and still no luck.

the mechanic's final diagnosis on the bill is that i have a "burnt valve on the #2 cylinder" and that i need a "head job". he assured me that it wasn't a blown head gasket and that the car should be fine to drive on the trip back to charleston where i could get it worked on around home.

the car still feels very rough while idling (~1K rpm). on the highway it felt great. obviously a bit strained when applying any type of load (on ramps, hills, etc).

the car is not putting out any type of excessive smoke, does not have a fuel smell and the oil does not have a milky or cloudy look to it. levels on the anti-freeze look fine and it is not discolored.

so my questions....

-what does a "burnt valve on the #2 cylinder" and need a "head job" mean?
-what should i expect for cost at a mechanic's shop?
-is this something i can do myself (with the help of mechanically inclined friends)?

honestly, i can't go putting $1500 worth of work into this car as its probably not worth that much.

in addition to the new plugs, cables, rotor and distributor cap, i've recently added:
-new tires
-new brakes
-new timing belt
-new headlights
-trailer hitch for a very small boat which i haven't even hooked up

thanks for any input!
-baustin

 

i should also add that the mechanic at the dealership said the cylinder had low compression versus no compression.

 

A burned valve isn't good news, nor is it a cheap fix. If you know what a valve looks like, the burned through part is the wide circular part which seats in the head to seal the combustion chamber. So, at a minimum, that valve will have to be replaced and that valve seat reworked so the new valve seats (seals). The head has to be removed to do this. There may or may not be damage to the piston and/or rings, too.

Years and years ago I burned a valve on an old junker VW Beetle which, as the car was exceedingly slow to begin with, barely made a difference in its (lack of) acceleration. But, it caused a secondary problem. No ignition of the gas/air mix in the cylinder, and somehow it holed the piston. So, gas/air mix entered the crankcase and severely diluted the oil quickly. I ran virtually straight STP for a while, but was always afraid of explosion.

 

thanks for the input.

is this something that i could potentially tackle myself?

is this along the lines of what i'd be looking at? (probably out of my league)
http://www.matthewsvolvosite.com/for...hp?f=1&t=26864

the quotes i've gotten have been $1100 - $1500... if a dealership/mechanic is going to be opening my engine and charging that price, should i expect only the "burnt valve on the #2 cylinder" to be fixed or would this be a rebuilt engine with all issues tended to? (obviously speculation) basically, my concern is that the engine get opened and the mechanic says, well you've got issues with the #3 cylinder and thats gonna be and extra $1500.

again, in the last few months, some of the work i've done...
-spark plugs
-spark plug cables
-rotor
-distributor caps
-tires
-brakes
-timing belt
-trailer hitch (that hasn't been used at all)

it kills me to think i just put this much money into my car and its suddenly dead-ish.

thanks!

 

Don't just get the known burned valve redone without first a compression test and leak down test on all cylinders. A large part of the labor cost of the job is removing the intake, head, gasket, reworking the cylinder head which you only want to do and pay for one time. The tests (done before disassembly) will give you or your mechanic a better idea is other valve and ring trouble exists. Then visual inspection on removal.

You're in money pit limbo. You've already spent some good money on the car, so you need to determine if new $$$$ costs are worth it or not. Probaby not right away as total repair costs probably have or will exceed value of car. But if you divide it out over 50K or 100K or whatever, it might be worth it. Is the trans, driveline, suspension, alternator, power steering,a/c, accessories like windows all working well? Volvos don't nickel and dime you, they !00 and 500 you. You've replaced a lot of things, so if all you need is the head work, probably worth it.

My 64 VW was a $100 car, so it wasn't worth repairing. Drove it until I got too scared and had saved some money, then junked it.

 

again, thank you for your feedback!

so tests I should consider performing myself...
-compression test
-leak down test

are these the correct terms I should be searching for?

any links off the top of your head to good DIY guides for these jobs?

 

Those are the tests. Similar, but different tools. Compression is "dynamic", that is, the gauge tells you the compression in each cylinder as the engine is cranking over (but not running). The leak down test is more "static" as is uses a known amount of pressure and shows you how fast each cylinder loses compression.

My advice: pay to have these done as by the time you buy both gauges, you're going to be spending money and probably/hopefully won't use these tools again. The mechanic shouldn't charge you a whole lot. They are diagnostic tools the mechanic would use anyway.

About doing the valve job yourself. Not unless you're good with wrenches.
To do this, you need to remove the timing belt, note cams position, have a torque wrench and a shop manual to tell you not only torque but tightening sequence to put head back on. Valve replacement isn't exactly like replacing a burned out lightbulb in a lamp at home, either. You need to "lap" the valve with (duh) valve lapping compound to get it nice and smooth and mated to the valve seat. And a lot can go wrong if you misposition the cam, don't properly adjust the timing belt and its tensioners.

 

Baustin-

I have a 99 v70 xc that had two valves that were bad, #1 and #4. I Took the head off myself, took me 7.5 hours. If you unbolt the intake and exhaust manifolds and scoot them back instead of removing them you will save time. It cost me $350 at the machine shop for the valve replacement and a pressure test. You'll want to change out the water pump, timing belt, tensioner and whatever else comes in that kit ($350); if you have more than 50K miles on those parts. Then install head. Be aware you need special tools to install the cams. So $700 to do it yourself.

 

hmmmm... interesting...

do you remember the kit you purchased?

i'm leaning towards buying a new (used) car, but am also considering keeping my current volvo as the dealership only offered me $500 on a trade in.

thank you malaka and jeffreydoctor for your input!

 

Probably. Volvo's aren't necessarily difficult to work on, but they are time consuming. I say that based on my experience with turbo models. Yours might actually be somewhat less involved, but it all depends on how much time you have to devote to it, and exactly how "mechanically inclined" your friends are.

If anybody ever decides to put that on a bumper sticker, I want one.

If your "mechanically inclined" friend has a compression gauge, you can get decent enough numbers without paying someone to do it. Do the standard compression test, then squirt a couple tablespoons of oil into each cylinder and re-do the test. If the numbers go up, you have issues with the rings. If they don't go up, it's the valves. If only one cylinder is low, and the number doesn't go up with some oil in the cylinder, then it's a pretty safe bet the valve is the only issue.

You probably wouldn't get much more that that if you sell it yourself. It's not a small job. Like I said (assuming your friend is helping), it's not particularly difficult, but labor intensive. How much time can you spare?

Basically all you'd need to do is pull the head off and take it to a machine shop. They'll clean it, pressure test it, check it for warpage and resurface it if necessary, and install a new valve. Then you just gotta put it back together. There are some critical steps in the process, but mostly it's just unbolting stuff, then bolting it back together in the correct order.

And, as has been mentioned, once you get it fixed you're good for a long while, given all the other work you've done. The evil you know (your car) is better than evil you don't know (another used car).