Driving with a burned exhaust valve

[sleddriver]

101: Please update. Any pictures before you sent off the head?

Traceytruesoaps site is now down. However, I did find parts of it archived.

Interesting reading here. Haven't taken any trips longer than about 400mi over a few days in quite awhile. I do admit to using 87gas regularly. The sled seems to run fine on it, though I'm going to re-think this. The delta-$ for 93 is about 60cents. I do use Redline Si-1 about once/yr. On my next long trip, I'll fill up with 93 and add a bottle of Si-1 as some consistent high-speed driving might be the best time for combustion chamber/valve cleaning.

The head has never been off the sled. Present mileage is ~ 214,500mi. Does use a bit of oil, but that might have been due to the leaking front CS seals. Recently fixed that. Definitely no blue smoke on start-up otherwise I'd smell it in the garage. One oxy sensor has been replaced, can't remember which. I'll have to look it up. Oil is M1 10w-30HM, changed about 8000mi with a new filter at 4000.

I long ago removed the plastic spark plug/wire vanity cover, as impeding the release of engine heat just makes no sense to this engineer. Further, I'm in the long habit of opening the hood when at home to dump the engine heat, before pulling the car in the garage. I don't do this when it's (actually) cold, but here we only have Summer & February.

I'm also wondering that when these cars reach a certain age/mileage, it would be of benefit to use one of the injector/combustion chamber cleaners where the fuel rail is disconnected and the engine runs straight off the cleaner for about 20min or so? I did this once after 180,000mi on my SAAB 900T using a BG product/system followed by a can of BG-44k in the tank and a thorough cleaning of the intake throttle valve, IAC motor.

After-thought:

Given many of these incidents have occured at hwy speed, and under load, on older cars, and coolant info was asked.....is anyone else bothered by the OEM horns in front of the condensor/intercooler/radiator, like I am? My indy says it doesn't bother as most air is directed from below. OK, but here we also must have front license plates. Their location would indeed impeed airflow at highway speeds, particularly when cooling is needed climbing hills, at altitude, heavily loaded, etc.

I think it's time I finally move them........

[cn90]

Traceytruesoaps info is archived in this forum database.

This is another good DIY:
https://www.matthewsvolvosite.com/forums ... =1&t=26864

[sleddriver]

Thanks CN90 for posting that!

[j-dawg]

I have never had an issue with inadequate cooling on my turbo car. On these cars, the coolant system's main issue isn't capacity, but retaining fluid - zillions of hoses, a failure-prone heater core, leaky radiator tanks, cracked heat exchangers for turbos and transmissions, etc are all stuff that needs to be maintained. Since I've bought my car I've replaced basically the entire system besides the pump itself. But if you can keep all the coolant in the system, the engine will run at high speeds all day without overheating.

[sleddriver]

Yep...been there. Done that. The sled's never overheated, nor left me stranded. Recently replaced all cooling hoses with Volvo. The heater hoses are still original however. I'll tackle them when it cools down. No burned valves yet. An oz of prevention here though is indeed worth a pound of cure and $600....and change.

The engineer in me just doesn't like anything blocking the front like that....bad juju.

[abscate]

The fans overpower any obstruction to flow through the radiator so if they aren't coming on, you have plenty of cooling capacity

We have front plates in NY too.

[101]

101: Please update. Any pictures before you sent off the head?

Here you go, sleddriver ...

Here's a picture of the engine with the head off:


Here are pictures of the spark plugs as removed. The way to interpret these is:
#3 was the origional burned valve
#5 valve burned out while driving the car home
#1 and #4 show significant heat damage from carrying the load of the dead cylinders on the drive home across the mountains
#2 doesn't look too bad.

Remember, these were OEM Volvo plugs with 2000 miles on them!




Pictures of the head:
#3 cylinder



#5 cylinder




and the other three





My rebuild included:

Head checked by a machine shop, valve job including replacing three exhaust valves (the two obvious ones and a third that my guy didn't like the looks of), the head resurfaced, and new Volvo OEM valve stem seals.

Volvo head gasket, head bolts and other parts.

Fuel injectors cleaned and flow tested

Turbo CBV diaphragm (mine had a hole in it)

ECT sensor (mine was original)

Fuel pump relay (mine was original)

Both O2 sensors (mine had somewhere around 175,000 miles or more on them)

Inspection of the PCV system (it was clean)

Replacement of any questionable looking hoses and vacuum lines.


I'm happy to report that 7000 miles post rebuild the car is doing great. Oil consumption went from one quart per 1000 - 1500 miles to next to nothing (latest is 1/3 quart over 4000 miles). My son drove the car from Cincinnati to Los Angeles for an internship assignment where it's enjoying a well earned vacation from the midwest.


I could never pinpoint a specific cause for my burned valve. It was probably some combination of using 87 octane, oil leaking onto the valves from valve stem seal leakage, deposits on the face of the valves and aged O2 sensors. I don't think ambient temperature or the cooling system was a factor in my case. I think the air guide, if installed, pushes a lot of air into the engine and radiator.

[cn90]

1998 S70 GLT with 185K miles, misfire cylinder #3.
I am still waiting for the compression tester (bought online and is in transit).

The car has many new parts (new wheel bearings, heater core, AC Pulley bearing etc. etc.), and I hate to get rid of this car.

Let's say the Exhaust Valve #3 is burned. I hate to do this job twice, so I am thinking:
- Re-use Intake Valves.
- 10 (2 Exhaust valves/cylinder) new Exhaust Valves.
- New Valve stem seals (Volvo OEM).
- No need to resurface the cyl head b/c this is not an overheat event, just burned valve.

So, back to the same questions that we discussed a few years ago:
- Exhaust Valve: what brand? Volvo vs Brand A vs Brand B?
- Exhaust Valve: what do I have in the car? Rmeuropean.com lists 6-mm and 7-mm valves.
- Anyone with experience re brand name can chime in?

[erikv11]

I bought one exhaust valve from Volvo. The rebuild now has about 60k on it, 260k total on the engine (and the rest of the valves).

We have discussed this before too - valves don't burn progressively, they do it all at once in an instant, when they have deposits that get hot and valves aren't closing, etc. Instead of spending on new valves, have the machine shop clean the old ones (valve job) and be on your way, unless the machinist sees a "bad" valve in the bunch to be repaired. If it happened to my car today, I would get one valve from a junkyard and give it to the machine shop with the head from my car.

I'd also pay to have it resurfaced, it is worth the expense. Either they clean it (finished instantly) or you spend several hours poring over it. You're going to have to do that to the block surface anyway, to get it sparkly clean. In the other thread where you said you would throw away the car I know you said you don't have a lot of time these days, so think about that too ... I would also have them clean up the cam cover; give the shop the valve stem seals, head, cams and cover.

Have you already swapped around the injector plugs, and/or the injectors themselves?

[cn90]

...
Have you already swapped around the injector plugs, and/or the injectors themselves?

Interesting idea, I have NOT swapped the injectors yet. I will do that soon.
Right now, I am waiting for the compression tester gauge. If I confirm no compression in #3 (I hope not), then the answer is there.
Right now, I am hoping it is "bad gas", my kid was driving down to Kansas City and filled with gasoline at a "decent gas station" along the highway. Then the misfire starts after that, so again I am hoping this is bad gas lol.