I've got a 1996 960. The radiator sprang a few leaks in it, which ultimately lead to the engine overheating and the head warping. My dad and I replaced the radiator, had the head resurfaced and replaced the head gasket. That's just a little history, now to my question.

It seems that almost at random, the car will hesitate when it is revved. It almost seems like one of the cylinders may not be firing for some reason. When we were taking the engine apart to replace the head gasket, we noticed alot of oil sitting on top of the valve cover and around the spark plugs, which is due to a leaky oil cap. Is it possible that either the overheating or the oil getting around the ignition coils has damged one or more of them? The thing is, the hesitation is very random. Sometimes it will do it right after I start it, sometimes it does it after its been running for a while and I get to a stoplight. But, it always idles fine. Also, sometimes when its idling (I keep my windows open alot) I can smell raw gas in the air, which leads me to think that a cylinder or two isn't firing.

Anyways, I know that was kind of a scatterbrained post, and I appreciate any and all help.

 

I would look at the coils. They are known to go bad. Also look at the wiring at the plugs for the coils. They are known to come out of the coils to.

Make sure your Fuel rail isn't leaking. They are known to leak gas from time to time.

 

Alrighty, thanks! The oil seems to have broken down the material that holds the leads in place in the wiring plugs so it's possible that they aren't making good contact. Also, I'll see if I can find some replacement gaskets for the injecotrs on the fuel rail. We've had them in and out so many times I guess it's possible they may be leaking a bit. Again, thanks for the suggestions!

 

did you resolve the problem? first, did a check engine light come on? if a coil is bad, the car will misfire and a check engine light will come on. I have a 960, the check light does not come on, but i have a hesitiation while on the freeway, the revs come down, i have to gun it to bring it up again. If i proceed to the exit and let it idle, it will idle to stall..but restart immediately. I checked the vacuum lines and replace many, checked for vacuum leaks, etc. to no avail. any ideas.

 

A bad cam sensor or coolant temp sensor will cause the same problem.

 

hello, wondering if you ever fixed your problem. I have a very similar problem w/ my '90 turbo wagon. Sometimes it runs perfect, but most of the time (after warmup) it will idle down, sometimes stalling, when I slow down. Does the same thing as yours does on the freeway. It seems to happen when the rpm's drop. I am about to order an idle control valve to see if it fixes the problem. Gas mileage also sucks bad.

any help would be appreciated

i

 

Where is all the oil coming from, the 960 engines I worked on had a two piece head after the bottom is installed you had to use sealant supplied with the head gasket and apply it to the top piece. Also if any of the numerous small bolts were stripped oil will leak around the bolt. If this is the problem buy a longer bolt that will tighten but not bottom out. All oil leaks have to be stopped.
If trying to buy other connectors go to a normal junk yard not a Volvo specialty junk yard shop they way over charge.

 

Advance Auto and Auto Zone will run a computer scan on the engine for free you might try this before spending big money for something you may not need.