Driving with a burned exhaust valve

[Ozark Lee]

My source for low octane and burned valves was an observation by Jimmy57 that when gasoline got in the $4.00/Gallon + range that they suddenly saw a rash of burned exhaust valves on turbo engines in the dealership. It makes sense.

...Lee

[j-dawg]

93 on every tank and I hit 5,000 or so probably once a day. My car has consumed oil through the valve stem seals at a pretty high rate (~1000mi/qt) since I got it 30,000 miles ago. No burnt valves.

It's one data point, but I stopped worrying about that leak and burnt valves a long time ago. Not saying it couldn't be true, not saying it won't happen to me, but at least in my case, leaky valve stem seals and occasionally revving it out do not mean instadeath. We need a burnt-valve data thread, just like the snapped-timing-belt data thread we have.

[rspi]

I don't know why anyone would have an issue with buying 91+ with gas prices so low. When I ran the numbers, I got a little better mileage with 91+ which offset the cost.

We are not all youtube internet celebreties like you, in my neck of the woods there is a huge price difference between 87 and 91; thats where they get you. I use 91, but they screw you, costing 91 way more than 87.

Huh? What does YouTube have to do with the price of gas? It is usually about 30 cents per gallon more around here. Some places as much as 60 when gas was $3.40 per gallon.

[mecheng]

RPSI: It was a joke, I forgot the smily face.

J-dawg: I was just thinking this, I thought there was a database, but if not I will start one.

[rspi]

RPSI: It was a joke, I forgot the smily face.

Oh, because I was hoping that I was missing some kind of travel benefits or something that I needed to cash in on.

[101]

update

Got the car back home to Cincinnati today. It was 450 miles of absolute torture.

It ran poorly as expected with the #3 cylinder out of commission, but the bigger issue today was absolutely no power going up hills. That was not a good situation crossing the Appalachian Mountains through Virginia and West Virginia. I had to climb every hill in lower gears. Some of those 5% - 7% grade hills required driving on the shoulder of the interstate in first gear at 20mph. Towards the end of the trip I had to keep the car in 3rd at 65mph because it would shake itself silly at anything less than 3000 rpm.

I'm wondering if I'm having some other related issues such as a plugged cat, weak fuel pressure or a weak coil. Today's performance was too poor to attribute to just one dead cylinder.

It's going to get too cold to work on it this week.. Which is probably good as it may take that long for my sphincter to relax. But I will update this thread as the diagnosis and repair continues.

[abscate]

Glad you are home safe. That does sound more than just a dead cylinder problem

I glad we both made the " in trouble far from home but made it" club

[101]

UPDATE

I removed the head today. It took me 5 hours from start to finish doing it by myself in the driveway with the front of the car on ramps. This was my first Volvo head removal.

Overall, the job went well. I was pleased at the quality of the hardware that Volvo uses to put these cars together. After 19 years and 200K miles, I only had one stubborn fastener – the lower one on the thermostat housing. I was able to gently work it out. I’ve worked on many lower mileage cars where the fasteners were much more corroded.

A special shout out to Robert (rpsi) and his YouTube video series and the tutorial posted at Volvo 5-cylinder: How to Replace the Head Gasket. These were invaluable and gave me the confidence to do the job.

General Observations …
• The inside of the engine looked great. The oil passages were squeeky clean and the cylinder walls still have a nice cross-hatch pattern. Mobil 1 has made a believer out of me.

• The cam cover took some patience to remove. I was very careful to use the pry tabs and raise it evenly. I elected to leave the timing belt on and keep the cams on the head rather than lock them to the cover. Once the cover was off I took the timing belt off and removed the cams.

• When removing the exhaust manifold, I found the nuts on #4 and #5 were already loose. I had noticed the telltale sound of an exhaust leak but thought it was all related to the split pipe at the back of the cat.

And Now the Disassembly Findings ..
I did not do another compression test before tearing into it.
• The removed head shows one burned exhaust valve on both #1 and #3. There are noticeable deposits on the exhaust valves of #1, #3 and #5.

• The spark plugs for #1 and #4 show melted electrodes. The other plugs look OK.


That’s why my car was running so badly. #3 was already dead. #1 died on the way home. And the #4 plug gap was way over spec from melted electrode. Basically, I was running on two cylinders.

The rebuild planning in in process. And I'll try to post photos shortly.

[rspi]

LOL, Ouch! Dang! Yikes! All kinds of issues there. I have heard that in the past, more than 1 cylinder burning a valve. Tough break. I wonder if you have low fuel pressure or something causing the car to run lean.

[101]

yeah - she's apparently pretty sick.

I'll break out my trust fuel pressure gauge and check the fuel pressure.

As part of the rebuild, I will be installing only Volvo OEM or equivalent parts, and:

- a set of reconditioned fuel injectors (mine are original, the o-rings are dried out and two of the plastic discs decided to attach themselves to the intake manifold when removing the fuel rail)

- a new catalytic converter (mine is original and has a break in the pipe after the cat)

- both oxygen sensors (they are at least 150K miles old)

The head is off to the machine shop today.