Driving with a burned exhaust valve

101 · Post by **101** » 30 Jan 2016, 19:55

MVS:

I lost cylinder #3 on my 1998 V70 GLT (211K miles) while driving through the mountains of West Virginia yesterday. I limped the car to my destination in Charlotte, NC.

I did the diagnostics this morning and confirmed zero compression on #3, with no other head gasket related symptoms. I've disconnected the fuel injector for #3 to stop dumping fuel into the cat. The car will start and run but with the miss from the dead cylinder.

Here's the problem - I'm 450 miles away from home. I'm sure I could find a shop in Charlotte that would be willing to do a valve job for $2000 or so. I can do this work myself (plus sending the head out) for much less at home.

Would I hurt this car if I tried to gently get it back home on 4 otherwise good cylinders?

Thanks!

Post by **erikv11** » 30 Jan 2016, 20:50

I've never driven one that far but I would expect it will be fine if you take it easy.

And/or pick up this one while you are there, try getting it home first: https://www.matthewsvolvosite.com/forums ... =6&t=74062

Post by **Ozark Lee** » 30 Jan 2016, 21:26

I've been driving the '94 with a bad valve for about 5,000 miles. The exhaust "pings" every time #1 hits the top of the stroke and it idles like crap but on the highway it isn't that noticeable except on big hills. It will start throwing codes but it should get you home without any problem.

...Lee

Post by **rspi** » 31 Jan 2016, 01:34

What Lee said. You can probably drive it 100,000 miles as long as you don't mind the rough idle.

Having the injector disconnected does more good than save the cat, it also saves the oil ring in the piston and rest of the engine by not dumping fuel in it. The raw fuel will burn the oil ring on the piston and start dumping fuel in the oil. Then the fuel would contaminate the oil and the rest of the seals, etc.

Post by **rspi** » 31 Jan 2016, 01:36

There was a guy on here that drove on a burnt valve for about 8 months before he finally checked compression. Was driving me nuts. Lol

101 · Post by **101** » 31 Jan 2016, 07:54

erikv11 wrote:And/or pick up this one while you are there, try getting it home first: https://www.matthewsvolvosite.com/forums ... =6&t=74062

Funny you mention that car That's EXACTLY where I was headed when mine took a dump. I spoke to the owner in detail about the car and low and behold it also has a burnt #3 valve. Kind of a spooky coincidence. If I successfully get mine back home I may still pick that one up. And I'll know how to repair it, right?!

.

Ozark Lee wrote:I've been driving the '94 with a bad valve for about 5,000 miles. The exhaust "pings" every time #1 hits the top of the stroke and it idles like crap but on the highway it isn't that noticeable except on big hills. It will start throwing codes but it should get you home without any problem.

Yep. On the interstate in flat areas at speed it's not bad. Increasing the rpm's by shifting to 3rd gear when climbing hills made a bit of an improvement.

rspi wrote:What Lee said. You can probably drive it 100,000 miles as long as you don't mind the rough idle. Having the injector disconnected does more good than save the cat, it also saves the oil ring in the piston and rest of the engine by not dumping fuel in it. The raw fuel will burn the oil ring on the piston and start dumping fuel in the oil. Then the fuel would contaminate the oil and the rest of the seals, etc.

[/quote]

Thanks for confirming. Makes perfect sense that the unburnt fuel would lead to no good left to its own devices.

Thanks everyone for the confirmation about driving it home. I'll definitely take it easy and once home it will not be driven further.

I just did a full timing belt /water pump / PCV / all fluids / 30K service a month ago and full brakes / rotors / front wheel bearings / CV boots / control arms / tires last summer. I really didn't want to let it go after all that work. And now I feel a lot better knowing that I won't have to take a chance on a shop that may or may not do the quality of repair that I know I can do at home.

Post by **rspi** » 01 Feb 2016, 08:38

Oh, almost forgot... I was wondering, how long have you had this car? How many miles have you put on it? Do you drive aggressive sometimes or just baby it. I am trying to support / dismiss my theory that these cars burn valves because they are driven to passively.

Here is my thoughts... The valves are getting build up on them with leaking valve stem seals, then start pitting the valve edges, not seating well. Then ownership changes to a person that will run the RPM's up above 3,500 from time to time. Within 5,000 miles a valve or two burns. Ouch!

I purchased my car, which was driven by a fire chief before the PO got it. Driven hard daily is my guess. It does have leaking valve stem seals but I do drive it spirited at time. I have put about 105,000 on it.

Another guy I know purchased a '99 V70 R. Drives it hard and burnt a valve in about 3,500 miles. I got a '96 850 T5 and drove it like an old lady for almost 2,000 miles. Sold it to a girl (very cheap) and she drove it like she robbed a bank. Four thousand miles later she burnt 2 valve.

Anyway, I'm thinking these cars really don't like being driven like they are about to fall apart, then switched to semi aggressive use.

Post by **mecheng** » 01 Feb 2016, 10:52

But wouldn't driving aggresively cause valve stem seal wear? I think occasionally driving aggresively would be good to spin the valves but I don't see how continuously driving hard would do any good. When you drive hard, you get a lot of heat generated in a Turbo engine, especially in the hot desert like places. I'm sure most of the qualifying testing was done in relatively cold Sweden.

The 850 I have was driven very passively prior to me owning it, so far so good. I think octane might also have something to do with it.

Post by **oragex** » 01 Feb 2016, 12:11

I am also curious about the reasons mentioned by rspi. While I drive a P2, I noticed the camshaft solenoid was stuck - it won't activate properly at higher rpm because the first owner was driving it too slowly. I wonder how this can affect the valves once the car passes into the hands of a more spirited driver. I also wonder if the injector flow might have something to do with a burned valve since a slowly driven car will develop varnish inside the injector causing poor spray pattern ?

101 · Post by **101** » 01 Feb 2016, 15:26

There's probably something to rspi's theory.

On the good side - I've owned the car since new. 211K miles on it now. I've always meticulously maintained it per the Volvo recommended schedule and its had Mobil 1 oil changes every 5K miles. The times I've done the PCV system its clean, clean clean. There's no noticeable smoking at idle or on acceleration that would indicate worn rings, turbo seals or valve stem seals, although it does consume about a quart of oil every 1500 miles now.

However - I AM guilty of running the car on 87 octane fuel (generally Shell because the car hates about every other brand), and I do drive it conservatively - more so recently since the 210K timing belt interval was coming up and I was on my original water pump. The run through the West Virginia mountains last weekend (75 mph road speed with strong winds and maintaining that speed up the grades) was the hardest and longest I have driven the car in at least 3-4 years, short of the occasional few seconds of full throttle acceleration when someone pisses me off while driving around town.

I should probably add that my oxygen sensors are old (150K miles - but fuel economy is still very acceptable); In the last 6 months I've developed an exhaust leak from a cracked pipe at the rear of the cat (its more noise than actual leak), and other than the occasional bottle of fuel injector cleaner I have never used Seafoam or any other products in the engine. I haven't seen an OBD codes show up for anything other than the evap system for at least 15 years which may be some sort of a record on these P80 cars.