Bought a 1999 S70 early November as a "reliable" car for my daughter. I've had 3 Volvos over the years. Took it to my mechanic who told me I was getting a sweet deal, had it tuned up and it worked.....for about 2 weeks. The ETS light and check engine light came on intermittently. Gave her the car and it started to misbehave at stop signs becoming very sluggish etc.

I see many posts on this subject over the years and notice the problems can be the air mass meter or the electronic throttle sensor. My mechanic gave up and now it's with the dealer.

Symptoms: initially shows no codes, then after 14 miles or so of driving it gets sluggish and nearly stalls. The dealership changed the air mass meter thinking it would do the trick and it did until they drove it again and it went bad. Now it's showing a code on all cylinders. My mechanic had just changed the spark plugs and they were clogged again. He says its running too rich.

The dealership is checking the fuel pump. My mechanic says it's not the fuel pump....maybe a vacuum causing a sensor to add too much fuel.

I'm just trying to get this fixed cost effectively. I noticed many of the posts regarding this issue are several years old. Has anyone figured this out in the last couple years?

Thanks!

 

If it is at the dealer, I'm sure they will figure it out soon.

 

That's my hope too. Not trying to out-think the experts - just trying to be an informed consumer. Probably should have read up on this model prior to purchase, not after!

 

Hmm. The sluggish feeling is a prominent thing indicating the piston rings could be damaged. Does it guzzle to much gas too or leak any fluid?

 

They are trying an O2 sensor after changing clogged plugs. Hopefully this does the trick!

 

These cars are high maintenance but great cars.

 

The dealer should be able to fix it quickly and not guess as to the parts to replace. "trying the MAF" is not the way the dealer does things. They hook up to the tester, run the diagnostic and measure. Is this a volvo dealer, or is it a dealer that is selling the Volvo. It takes a minute to test the fuel pump. You hook up the fuel pressure tester and turn on the pump. The fact the car runs and its running rich tells you its not the fuel pump. Its an odd diagnosis.

The 14 miles issue is the engine switching from closed loop to open loop. In other words, as the engine heats up the fuel, air, timing switch to variable control through the computer.

Too rich would not be indicative of a vacuum leak. I would suspect the MAF, which has been replaced as you said; or the IAC,; o2. You didn't say if all 5 cylinders have fouling. If it's 1 cylinder it could be an injector leaking. If its all 5 it would be a fuel/air delivery issue. An O2 sensor could cause that, but it would throw a code.

Maybe you could list the codes.

 

This was a Volvo dealer. They tried the MAF but after it did it again thought it might be the fuel pump. My non-Volvo mechanic said it's not the fuel pump and like you felt it could be a vacuum issue. The dealer put 2 senior techs on it and they feel its an O2 sensor. Unlike the MAF they said once installed they can't take it out. They were putting the old MAF back in.

All cylinders fouled clogging the newly replaced spark plugs again. They were replacing them. They said it had coded, but I'm not sure which codes were indicated. They are installing the O2 sensor today. Fingers crossed. With diagnostics of 3 hours the dealer has indicated a price of $875. Does that sound right?

 

$900 would seem outrageous but its likely not....


The O2 sensors at the dealer are probably in the $300-$400 range, plus labor, if they replace both.


Sparks plugs plus labor are expensive at the dealer. I was replacing plugs on the Acura we have. The parts place didn't have the NGK plugs in stock ($4-$5 each). I was in the Acura dealer for a dealer only part so I handed the clerk the old NGK plug and asked for 6. When he handed me the invoice the plugs were over $20 each. I went back to the parts place and bought Denso plugs for about $3 each. Labor is also expensive because they charge by the cylinder for that kind of work.


The MAF labor would be for taking it out, replacing it and then taking it out and putting the old one back in.

 

Sorry but you could not have found a more un-reliable car. Volvo changed at least 3 major systems in MY 99 and had chronic problems with all of them for several years to come.

BTW: It's a common misconception that techs at the dealer know what they're doing; I am here to tell you that's not necessarily true. It may be, and often is, but by no means a guarantee.

Surprised neither tech has not focused on the ETM as yet since you have an ETS fault; that's one of the three systems they "upgraded" in 1999 MY from a reliable mechanical system to a failure prone drive-by-wire system. Xemodex has the fix for about $500, but you won't hear that from the dealer techs.

You also said CEL was on but didn't mention what codes were set; that would be helpful. And the mileage on the clock?

 

If you have a bad fuel / air mix, it can foul the plugs real quick. It is not hard for a tech to check fuel pressure, if it's low, there may be a problem with your fuel pump. But I would focus on getting the CEL light dealt with.