1994 850 Engine problems

AlbaD · Post by **AlbaD** » 14 Jul 2004, 16:39

Hello. I am hoping you can help me with this problem. My 1994 Volvo 850 has 102,000 miles on it and has developed a problem with the engine.

Since last February, intermittently it happens where the engine doesn't start. This happens from time to time. After some repeat occurrence and discussions with the Volvo dealership repair shop, I have learned that the problem is that deposits have built up in the engine. They say this happens because I take many short trips (1-2 miles), and that I need to drive the car "harder." They say they have seen this before on Volvo 850s, even on some new cars. In cars under warranty, they replaced the engine head. For me, this would cost $1200.

For now, there is an easier solution. They explained to me that once each month, for 1-2 miles, I should drive the car at high rpm (5-6 thousand). This will cause the valves in the engine to come completely open, clearing out the deposit. This is supposed to prevent the problem from happening again. I did this for the first time on July 1, and within a week the car started leaking oil. I found the cap on the oil was broken. The cap was replaced and the oil filled and cleaned off the engine.

Now the car should be fine, but I have not driven it much since then because I don't want the engine to overheat or catch on fire.

What do you know about this problem? If I replace the head on the engine, can I expect the car to be good for at least a few more years? I only drive about 7,000 miles per year, mostly in town. I have heard that there is sometimes a problem with the older 850s where oil starts to leak from the back of the engine. Although I don't think I have this problem yet, anything is possible.

Any advice, knowledge or information is much appreciated.

Alba D.

Post by **matthew1** » 14 Jul 2004, 17:01

To verify what the mechanics told you, you'll have to explain exactly what happens when your car doesn't start. Does it turn over? White smoke from tailpipe? Blue smoke? How many cranks does it take? When did you last have the spark plugs changed? Air filter?

When was the last time you used a fuel treatment product like STP Fuel Treatment?

Out of every 10 drives, how often do you get the temperature needle to the middle (normal) range?

What they say about driving your car at 5-6000 rpms to clear out deposits around your valves is correct. Only without reliable diagnosis of the problem, we don't know if this is the correct solution.

Guest · Post by **Guest** » 14 Jul 2004, 19:37

Hi Matt,
Thanks for your reply. To answer your questions. The car starts to turn over, but doesn't actually turn over. I don't know if there is blue or white smoke from the tailpipe because I didn't look there. As to how many cranks does it take, it doesn't turn over at all. What has happened is that after an hour or two it does start no problem as would be normally expected. As to spark plugs and air filter, these things were checked by Volvo and/or done as per the regularly scheduled maintenance. I have never used fuel treatment.

I don't know too much about cars, but I would like to know if my car is salvageable and what degree of risk of future serious problems there is. Have you heard about these kinds of problems with the 850?

Alba

Guest · Post by **Guest** » 14 Jul 2004, 19:40

And one more thing, the needle is always in the normal range. No warning signals light up on the dashboard.

Alba

Post by **matthew1** » 14 Jul 2004, 19:50

Yea, I've read about it... it's called the Lawnmower Effect. Meaning, you have to move the car to get to the lawnmower, so you start the car, move it 20 feet, and turn it off.

But it does not sound like you have this problem if your temp needle always gets to 3 o'clock -- normal.

So you turn the key, it cranks and cranks, but does not catch -- is that a correct summary?

Tsquared · Post by **Tsquared** » 15 Jul 2004, 05:58

Anonymous wrote:As to how many cranks does it take, it doesn't turn over at all. What has happened is that after an hour or two it does start no problem as would be normally expected. As to spark plugs and air filter, these things were checked by Volvo and/or done as per the regularly scheduled maintenance. I have never used fuel treatment.

If it an intemittant non-turn over problem I would look at the battery cables, the battery and then the starter.

Per the dealership going on the assumption that the engine is starting to carbon up due to short trips that is a different matter. Use a good top end lubricant (Marvel Mystery Oil, Seafoam, or Berryman Total Combustion System Cleaner Kit) that can be added to the oil in the crankcase. Seafoam the intake (still tring to figure out the best way to do this - I will send Matthew Pics when I do it). And add a high detergent fuel additive to the fuel tank evey 2K miles (Chevron Teckron, B&G Fuel additive, Seafoam). I would also take the car out once a week and drive it for about 20 minutes at interstate speeds.

Good luck,

T

Guest · Post by **Guest** » 15 Jul 2004, 07:55

Matthew and Tsquared,

Thank you so much for your replies. Matthew, yes, you are right. The car cranks and cranks but does not turn over. Tsquared, I will try what you suggest about adding treatments for the engine.

If the dealer is right about the carbon buildup, is it better to do the engine work sooner rather than later? Or can I stave this off for some time by applying these treatments? How long might this work? Does this have anything to do with the other problem I have heard about in the Volvo 850, where oil starts to leak from the back of the engine? Is this a prelude to the oil leakage problem? I don't know anything about engines. I appreciate your help.

Alba

Post by **matthew1** » 15 Jul 2004, 10:25

Let's organize this discussion.

Does this have anything to do with the other problem I have heard about in the Volvo 850, where oil starts to leak from the back of the engine?

Problem 1: Rear main seal, right? I would have the dealer or an independent mechanic inspect the flame trap for clogs. This can be a cause of blown main seals. If it's too late it's too late, but check anyway. Do you have oil leaks under the car where you park it?

Problem 2: As for the engine/head, these 850 engines are incredibly robust. Gummed up valves would degrade fuel economy and performance, but not cause much worse than that. I think they might be trying to make some money off you. "Might," because it's impossible to get a 100% accurate diagnosis over the internet. Take it to an independent Volvo mechanic.

Problem 3: 850 not starting... probably related to Problem 2.

AlbaD · Post by **AlbaD** » 15 Jul 2004, 14:20

Yes, I have oil leaks under the car. But this only started since I tried the thing the Volvo dealer told me, that is to drive it at high RPM once a month for 1-2 miles. That was last week. Does this mean it is the rear main seal? That is bad, right?

Post by **matthew1** » 15 Jul 2004, 14:26

Does this mean it is the rear main seal? That is bad, right?

You'll have to get under there and clean it off and then look again after you drive it to see where it's coming from. Again, it's the diagnosis over the internet that's difficult for me to say Yes or No. Or take it to another shop and ask them if you need a new rear main seal.

If it is the main seal, then Yes, that's bad.