I've got a 740 GLE (16 valve) that is having some engine problems. Recently the check engine light was on. Took it to the dealer (my wife's decision, it was her car at this point), and the tech cleaned the knock sensor. He said the engine had rod knock, and that it would need a new engine at some point. (To his credit, he wasn't trying to get more money out of me; he was trying to discourage me from putting any more money into it.) Anyway, since the engine does seem quieter after it is warm, I suspect it is only piston slap. Still, the car is not running well. Last night I could hardly get it out of its parking space after it sat at the airport for 4 days. I couldn't keep it running until I finally sat in the space giving it gas for about 10 minutes. I'd like to have another mechanic look at it. I don't want to go to the dealer, and I am just trying to decide whether I need to go to someone who calls himself a Volvo specialist. I have a good garage---a Shell station---only three blocks from me where I wouldn't hesitate to take most cars, and where I feel very confident that I won't get completely ripped off. (Their prices may not be the lowest, but they won't lie to me.) I am just wondering I can expect them to be competent to really evaluate the engine and help me decide whether getting a replacement is necessary, or whether I need to go somewhere that deals exclusively with Volvos (or at least with foreign cars). I assume that my Shell station would not be the place to go to if I had to have the engine replaced?

I've had various problems with my 16v. Usually the engine itself is not the problem. I second the motion for the AMM. Had a similar problem and could not figure it out. Took it to a Independent and he diagnosed it, I ordered the part overnight from FCPgroton.com.

On the knocking noise, I have something that sounds like piston slap, rod knock, and I've tried to pinpoint it. I sounds like it coming from my auto trans. From the little breather plate on the bottom! Anyway the car runs fine.

good luck with yours,

jc
--
1985 740gle na, 1990 740gle 16 valve

If I dare to make a diagnosis from afar your symptom sounds like a failed mass airflow meter. Most mechanics can't diagnose them ,only replace them. Even when they test out with resistance measurement they often don't work right anyway. Expect to pay $150-$250 for a rebuilt.
Also ,replacing the belt at 50000 miles(and all the seals behind it ,incl. waterpump) is super important on the 16 valve engine. I know, I have a head with 6 bent valves sitting on my workbench. Bought that way from someone who didn' replace the belt.

Usually its free, to get an opinion from a greasemonkey.
So why not go to 3 or 4 Volvoshops and ask their opinion,
but WITHOUT giving any repair order.
Sometimes they ask 20 $ for a more extensive diagnosis.
But after 3 Volvomech-diabgostics you probably know much more.
Just tell them the truth, you want a few independent
opinions, and every reliable trustworthy mech will agree.
And remember, if its a big problem it can cost $$$.
Better you find out in advance, what you are going into.

In your case, I would check the timing belts,
but its hard to diagnose from here.

The local shop will probably replace all the parts on the car one by one, and fix the problem by process of elimination. Eventually, you will find that this gets to be expensive. Most of us went through something like this at one point or another, before coming to the conclusion that some research on independent Volvo specialists and some inconvenience in getting the car to them was worthwhile over the long run. I drive 25 miles to my mechanics' independent Volvo repair shop.

Philip Bradley

You do indeed need somebody familiar with the car and the engine, which most mechanics are not. An independent Volvo mechanic, specializing in Volvos and other Euro cars, is the best bet. The fact that your mechanic "cleaned the knock sensor" is an indication that something isn't right: one does not do that. Take it to somebody who understands the car.

This is a little off the subject, but isn't it possible to "clean the knock sensor?" Probably it's more accurate to say, clean the connector, right? I did that once to clear a check engine light. Worked good for me.

Actually, it was the tech at the dealer who cleaned the knock sensor.

Sometimes the Techs at the dealer are not so hot. The top mechanic for the top Volvo dealer in my area reportedly makes $22 per hour, plus a commission on parts. My independent mechanics get $48 per hour. You'll find that many of the independents were the better mechanics at the dealers. I stopped using dealers about 15 years ago.

Of course, there are good mechanics everywhere, at dealers, at non specialty shops, etc. Sometimes you get lucky and run into one. I try to hedge my bets by sticking with the independents, and even those I talk to before selecting one when I move to a new place.

Philip Bradley