1999 V70 B5254T VVT Head Removal Advice Needed

[Ozark Lee]

That definitely explains no compression!

What is weird looking is that, particularly on number 4, the valve looks chipped rather than burned. Number 5 looks just like what a burned valve usually looks like with the irregular piece burned out of it but on number 4 it looks like the missing chunk is smooth and regular.

A couple of things usually lead to burned exhaust valves. Leaky valve seals and crappy gas. Even on my LPT cars I still use at least mid grade gasoline. The valve seals are self explanatory and I would guess you are going to change them anyway.

...Lee

[j-dawg]

how come you can burn valves in two cylinders?

having never experienced a burnt valve myself, i'd assume that after the first valve went the engine would run poorly enough that the engine would be stopped shortly, whether as a direct consequence of the failure or by driver intervention.

so what are the chances that in between the first burnt valve and engine shutdown, a second valve is burned? or am i missing something?

[Ozark Lee]

The car continues to run, even with a burned valve on one cylinder. It doesn't run well but it will run. By the time the second cylinder goes it is running bad enough that it really gets your attention.

Particularly when low octane gas is a big contributor all of the cylinders are subjected to the same thing so the results tend to be about the same.

...Lee

[deepsouth]

Yeah, given that the bottom half looks good, I'm going to take it to the local machine shop for repair and restoration. Picked up the car for dirt cheap (almost free cheap) because my friend didn't want to deal with all this and bailed. The other exhaust valves also have crusty type deposits that look suspiciously like barnacles. It's a beautiful blue wagon and the interior is in great shape so it's a good hobby car.

Although attempting to drain the fluids I've found that the oil pan plug is completely rounded and the plastic cover for the cartridge filter was apparently installed by superman, as it won't budge. Can only guess as to when the last time the oil was changed. Am going to hunt down some Irwin bolt removers tomorrow and find a filter wrench with a longer handle (it looks like at some point someone pried a screwdriver into the plastic and tried to hammer the cartridge holder off, leaving it cracked). Either way, right now it isn't budging.

Apparently 1999 and newer uses a special 86mm filter wrench with 16 flutes?

[Ozark Lee]

The filter wrench is its own animal, the filter is a paper cartridge that goes back into the housing.

Assenmacher, and likely others, makes a nifty wrench that snaps onto a 3/8" drive ratchet. I think I bought mine through Amazon (Using Matts link of course). Search Assenmacher Volvo filter wrench on google or through amazon and it may bring up some alternatives. I seem to recall that I pair around $18.00 for it and then saw one cheaper somewhere else.

...Lee

[donis222]

I have heard various answers as to why these engines burn valves. My experience leads me to believe that not using premium gas is the cause. I've done 3 burned bvalve heads and all owners said that they were using reg.
Understand this, using premium does not cost anything. If you moniter your MPG you will see an increase that compensates for the extra cost!

[precopster]

The extra heat of detonation can be a good reason for burned valves however many people believe that oil dripping down the valve from failed stem seals is also a major contributor. The oil turns to carbon deposits which stop the valve from fully closing, then the flame path goes past the valve face and onto the valve seat causing holes in the valve. Make sure you have new stem seals fitted before sealing that engine back up.

[donis222]

Those engine restore additives that are sold in autoparts stores and walmart have a chemical that softens the rubber in seals. I used to think that they were BS.
I have fixed both engines seal leaks and a balky transmissions that would not shift into gear when cold.
Takes a couple of weeks to work.

[jxkeefe]

I have also experienced the sudden catastrophic exhaust valve failure twice separated by 40,000 miles in the same engine but different cylinders. The engine is a 2.4L Model B5244S6, PZEV, VIN Code “64” in my 2005 Volvo V70 wagon. Back in 2012 while driving about 60MPH for at least an hour on a main highway, I had a piece break off one of the #5 exhaust valves. The car had 135,000 miles. The car is not raced or even driven hard as my wife and I are retired. I had a dealer, Capital Motors, Albany, NY, pull the head, replace the bad exhaust valve and the other #5 cylinder exhaust valve and reassemble. They did a very good job although it was an expensive job. Neither the dealer’s techs nor I had ever seen this in the past. We all figured it was a manufacturing defect with just that valve and elected to not replace any of the other exhaust valves in the other cylinders. I started out many years ago as an aircraft mechanic and had seen burned valves and valves the head of which broke off (my VW bug had the broken valve smashes piston issue) but I had never seen a valve with a piece missing. The edges of the chip in the valve are relatively sharp where the edges of the burn in a burned valve are burned smooth. Usually a burned valve is caused by the valve not seating correctly due to it being stretched from heat and old age, the spring loosing tension, something breaks off upstream and lodges between the valve head and the seat or cheap valves. The valves need to properly seat to cool correctly and prevent burning. Ozark Lee’s idea that leaky valve seals allow excess oil to get past the seal which gets carbonized at the hot end of the valve and eventually builds up enough so the valve does not seat properly is also possible. However, this is an instantaneous catastrophic failure and not a gradual failure over time. There must be something that causes the valve to not seat that happens quickly since I had been on the highway over an hour with no sign of trouble before the sudden failure. The chipped exhaust valve looks just like the picture of the #4 cylinder valve - more chipped out than burned in the entry from deepsouth dated 05 Sep 2014 and pointed out by Ozark Lee 05 Sep 2014 18:28 or the entry from byeboy dated 01 Jul 2012 at 21:37. The edges of the chipped out piece are sharp like it broke off vs burned off. Poor quality fuel would not likely be a cause since these engines have active knock control.

In my experience, a burned valve usually starts out as a slight miss in the effected cylinder most noticeable at idle and over many miles gets progressively worse. There is usually a Vee shaped notch in the valve head. In this case there is a piece chipped out of the valve head and as mentioned, the failure was sudden.

I had the same thing happen again at 180,000 miles a few weeks ago but this time it was #3 cyl exh valve! This time I had been on the highway doing about 60 MPH for about 15 mins when the exact same symptoms suddenly happened. I had a datalogger connected to the OBDII port troubleshooting other issues (completely unrelated low fuel pressure 20 secs after a cold start at air temps below 40 degF) and I am fairly certain the engine was running fine before the sudden failure. While I have yet to pull the head, I am 99.9% sure that is what is wrong from compression testing ( zero PSI in #3 cyl) and how the engine behaved when the failure occurred.

So much for Volvo durability and dependability although my 96 Volvo has 283,000 miles and no issues like this. Maybe when Ford took over they cheapened up the valves among other things - I don't know and don't know how to find out. I'll bet Volvo will never admit it and besides Ford doesn't own them anymore. At 135,000 miles the car was way out of warranty and Volvo would bear no responsibility. Hydraulic lifters solved many burned valve issues on aircraft engines during WWII. I have no idea why Volvo stopped using hydraulic lifters - cheaper to manufacture. Volvo never added a valve lash check to their maintenance checks for the car. This would have at least tipped me off that they were solid lifters. Yes, this is a water cooled engine but even water cooled engines should have the valve lash every once in awhile.

Nobody seems to definitively know why exhaust valves are failing like this. When the first failure occurred, in hindsight, I guess I should have changed all exhaust valves, the springs and the seals. I asked a couple of auto machine shops and head rebuilders what they do and was told by all of them they never test valve springs – just reuse them and reuse all valves that can be refaced and are not bent. I am not thinking a rebuilt head is the answer for this issue since the next failure is built in and who knows how long before disaster will strike again.

In my case, at 180,000 miles, the bottom of the engine is worn. I am following E. Showell’s advice ( see 17 Feb 2013 09:18 reply to Engine running on 4 cylinders) and having a used engine installed. With any luck I should get 60,000 to 70,000 miles from a used engine before the valve issue happens again. Maybe by then Volvo will relearn how to build a durable valve train! Hopefully the used engine will hold together until I get my money out of it.

If the bottom end of your model 5244S6 engine is still relatively good and you want to do a valve job, I would strongly recommend you replace all exhaust valves, springs and seals as well as resurface the head. There are qty 10 exhaust valves at around $80.00/each so it is not cheap. There is no cost effective way to tell how close the existing exhaust valve is to failure and it is a lot of work to change them. You might be able to magnaflux the valves but I don’t recall ever seeing that done in the auto engine world except maybe in racing. That would show cracks but not fatigue. Perhaps someone reading this might know.

I will certainly warn anybody that runs a Volvo - Vin code "64" - PZEV engine - engine model 5244S6. I am not sure what to tell them since there is no warning of the impending disaster except a reminder about the cat meltdown issue if the check engine lite starts to flash. I suppose one could do a complete valve job and put in all new exhaust valves (10 @ $80.00/ea ) plus new valve seals, new springs at about 100,000 miles and hope for the best. Not sure what manufacturer of exhaust valves I would use.

Jxkeefe

96 850 wagon blue
05 V70 wagon grey

[cn90]

On the issue of:

1. Replace only 1 valve vs all 10 exhaust valves.
This has been discussed many times here.
Due to cost consideration, most people replace only the bad valve and since most DIY, they consider that acceptable.
However, if one asks a shop to do it, then on the long run, it probably makes sense to replace all 100, but...

2. Cost is the problem as you mentioned.
Volvo knows there is a small market for these exhaust valve, so they jack up the price.

These valves probably cost $10 to make, but Volvo jacks up the price.

3. Re Brand.
I know MAHLE makes valves and pistons for BMW, so I'd not be surprised if MAHLE makes the valves for Volvo.
So, the choices are:
a. Volvo OEM valves @ $70-$80/each
b. Intervalve $10-$15/each
c. Osvat (Italian company) @ $10-$15/each. I see a lot of Osvat sold, so I assume this is a good alternative.

Anyone with any experience with these aftermarket brands?

4. Valve Stem seals:
Most people here say stick to Volvo OEM seals.