Head gasket update

Ghassan · Post by **Ghassan** » 26 Jan 2006, 18:30

Hi,

Car:
1998 S70 T5 Auto; 260,000km.
Severe cold climate operation in Montreal, QC, Canada.

I am posting an update on a peculiar loss of coolant that I observed in my car. This will help those who look up info on this problem (and related ones) in the future long after I am gone. The coolant loss, if you recall, was attributed to a failure of a head gasket.

[Original thread: https://www.matthewsvolvosite.com/chat/p ... php?t=6197]

Background (for recap):

Lately I had been noticing that my coolant level in the reservoir tank would drop to "Min" and stay there. I would top it up and over a period of 2 weeks it would seem to settle back to "Min". I have not seen any trace of coolant on the parking spot. One day I left the car parked and undriven for the entire weekend. Before walking away from the car for the weekend, I noted the coolant and it was at "Min" (engine still warm). The morning after the weekend, I found that the coolant, to my astonishment, had disappeared entirely from the tank. I failed to find any trace of coolant on the parking spot.
The car was taken to a garage and they reported that no visible sign of external leakage was found. They mentioned something to the effect that coolant residue was found in the vicinity around turbo and said that this indicates the head gasket may have failed. They said that the gasket will leak as the engine cools and this explains the loss over the weekend. The garage handed the car back to me and adjusted coolant level slightly above the "Max" mark.

Please note that I check engine oil often and never have found any trace of white milkish substance on the dipstick. This confirms that coolant is not going into the crankcase. Additionally, the engine temp. needle stays exactly at the 3:00pm position. In the summer I noticed that the needle climbed one notch up (I don't believe this is normal; I believe it should still remain at exactly 3:00pm position in summer). My radiator is clean.

Update:
Since the day at the garage ( 3 weeks ago), the coolant has settled to exaclty "Max" and is not dropping further below.

I will keep posting any further developments.

Thanks.

Ghassan.

Post by **pfeener** » 27 Jan 2006, 18:03

If you had that much coolant (I assume about a cup or more) leaking directly into a cylinder you would sense it when the car was started cold. The cylinder wouldn't fire until things dried out which will make the car idle very rough and you should see large amounts of white smoke out the exhaust. Pulling the plugs and doing a visual look-see should also help in isolating the problem. If it is a head gasket you should see it on the plug with the antifreeze.

Also if there was antifreeze leaking into the cylinder and sitting there overnight. It would find it's way past the rings and into the crankcase. If you don't see anything in the oil or antifreeze, I doubt you have a head gasket problem.

In addition. if you're burning antifreeze, the O2 sensor will usually turn on the check engine light.

Ghassan · Post by **Ghassan** » 30 Jan 2006, 09:13

pfeener wrote:If you had that much coolant (I assume about a cup or more) leaking directly into a cylinder you would sense it when the car was started cold. The cylinder wouldn't fire until things dried out which will make the car idle very rough and you should see large amounts of white smoke out the exhaust. Pulling the plugs and doing a visual look-see should also help in isolating the problem. If it is a head gasket you should see it on the plug with the antifreeze.

Also if there was antifreeze leaking into the cylinder and sitting there overnight. It would find it's way past the rings and into the crankcase. If you don't see anything in the oil or antifreeze, I doubt you have a head gasket problem.

In addition. if you're burning antifreeze, the O2 sensor will usually turn on the check engine light.

Hi,

Thanks for the reply. Here is my response:

At start-up, it didn't idle rough at all. I cannot confirm the white smoke.

The check engine light is not on and it never came on. The spark plugs were recently replaced under scheduled overhaul, however, no sign of fouling was found. I must remark that the problem of coolant loss was found after the plugs had been replaced already. The level is still at "max" when engine is warm.

You also mentioned that the antifreeze dripping into the cylinder would not find its way past down the piston rings over a two day period. I will keep this in mind.

Thanks.
Ghassan S.

White850Turbo · Post by **White850Turbo** » 31 Jan 2006, 06:39

When a head gasket is done on these cars, the exhaust manifold, turbo, and coolant lines for the turbo must be removed. My bet is that when they put everything back together, the coolant line for the turbo was arranged in such a way that it would no longer leak. Just based on the evidence which you had earlier stated, I really don't think the head gasket was ever faulty.

Ghassan · Post by **Ghassan** » 31 Jan 2006, 07:42

White850Turbo wrote:When a head gasket is done on these cars, the exhaust manifold, turbo, and coolant lines for the turbo must be removed. My bet is that when they put everything back together, the coolant line for the turbo was arranged in such a way that it would no longer leak. Just based on the evidence which you had earlier stated, I really don't think the head gasket was ever faulty.

RE: "coolant line for the turbo". Is the turbo cooled with the coolant? I thought it was the engine oil that was used for cooling the turbo?

thanks.

ghassan.

Guest · Post by **Guest** » 31 Jan 2006, 07:45

RANT

Man, I hate to read stories/theories like this because you know a mechanic worth his/her salt probably knew this but it was a convenient excuse to make more money. Don't mind me, maybe they honestly didn't know, just extra bitter today cause my 850 won't start. That's it, I'm done with this car if it's not the battery.

/RANT

White850Turbo · Post by **White850Turbo** » 31 Jan 2006, 13:02

Ghassan wrote:
White850Turbo wrote:When a head gasket is done on these cars, the exhaust manifold, turbo, and coolant lines for the turbo must be removed. My bet is that when they put everything back together, the coolant line for the turbo was arranged in such a way that it would no longer leak. Just based on the evidence which you had earlier stated, I really don't think the head gasket was ever faulty.
RE: "coolant line for the turbo". Is the turbo cooled with the coolant? I thought it was the engine oil that was used for cooling the turbo?

thanks.

ghassan.

The turbo's on these cars are cooled by both coolant and oil.