Volvo 740 Turbo - check engine, anti-lock, etc.

girlwithtools

Background: I own a '90 Volvo 740 Turbo with 155k miles but it received a 940 engine at 96k. Maintenance issues include a front passenger strut mount breaking, sending the strut into the hood, a foul brake job performed by Midas (a.k.a. My _ss) leading to a full replacement on the front passenger side, new air conditioning unit (the original dealer mixed the old with the new coolant), water pump and oxygen sensor (due to the nesting habits of mice). Now we have equalled in maintenance costs what we spent on the car itself.

The "check engine" light came on Friday and I swear I can pick up the rotten egg smell. I originally wondered if it was the catalytic converter, but the engine is cutting out occassionally - oxygen sensor again? Today, the anti-lock brake light came on. Add to it a serious sunroof leak. My first thought is "Will this ever end?" My second was "Where do I start?"

My goal is to get it running with no alert lights going off, get it in to be detailed and sell it (although I have been in love with this car forever). How do I troubleshoot the "Anti-lock" problem? Do I go ahead and replace the oxygen sensor and converter, crossing my fingers? Or should I just haul it to the shop and deal out the dough? Any thoughts/comments are greatly appreciated!

alcan

Replacing the catalytic converter without correcting what caused it to fail will usually result in another converter meltdown. Most common is an engine over fuelling, which 'may' be O2 sensor related. For the check engine light, start by going here:

http://www.batauto.com/Volvo.html

girlwithtools

Thank you for the link! Very helpful information and I will be digging under the hood tomorrow night. Question: Is this the $150 diagnostic check my mechanics are performing? If so, I'm dumbfounded. The more you know. . .

Any ideas on the anti-lock problem? I didn't see information relating back to that on the link. Can you tell I am overly hopeful for the "do-it-yourself" option?

alcan

I'm not sure what your mechanics are referring to, but diagnostic trouble code retrieval only is usually in the 1 hour labour range. Could be they check fuel pressure, scope the ignition system, etc.

For the ABS problem, try here:

http://www.batauto.com/cgi-bin/Forum/db_TalkToMeV2.cgi?forum_name=imports

girlwithtools

The speedometer and the temp gauges are bouncing all over the place. The speedometer bounces when I hit a bump in the road (even the slightest bump). The temp gauge will maintain at 0* and then pop up - like it was stuck. I'm thinking there is a short in the electrical?? Am I close?

alcan

Since more than one circuit is affected I'd be thinking an intermittent ground problem or loose connector at the instrument panel, or a cracked circuit board. With it warmed up, try wiggling the harness connectors behind the dash while you watch the temp gauge. Also try the same at the high density connector where the engine compartment wiring harness passes through the bulkhead. Btw, did you inquire re the ABS problem at the site I posted?

girlwithtools

I am eating your advice up! I bled the brakes as suggested, but that has not taken care of the problem. My father seems to think it is a leak in the back brake area (it's not the calipers, I just can't remember the name of the part). Hopefully, tomorrow night we can take it apart and get in a gander. At this rate, I'll need to get it off my hands before something else goes. And I thought they were known for their reliability??!!

lancerfixer

Have you visited http://www.brickboard.com yet? They've got a great section on 700/900 series maintenance FAQ, plus Q and A forums for specific questions. Volvos are known for their durability (not really to be confused with reliability-- they WILL eat money on their way to 300,000 or 400,000 miles.) Having said all that, I myself just picked up a one-owner 740 non-turbo (one less thing to worry about) sedan that I'm hoping will see at least another 100,000 miles or so while under my care. (it's got 102,000 miles and all maintenance records since new.) How the vehicle is maintained from new (this goes for any vehicle) has a large say in how long the vehicle will last. Having said all that, I think I did see something at the brickboard about fluttery gauges. I can't remember the exact fix, though.

lancerfixer

Getting your brakes done at Midas didn't help anything, either. However, you probably already knew that! :-)

girlwithtools

Ironically, the Volvo I bought was one owner, 112k, had all the repair paperwork and the repairs were done at the only new Volvo dealership in town. I almost called the original owner to find out about the engine snafu (it went from a 740t engine to a 940t at 90k). After the "My _ss" flub, I networked and found a wonderful shop in town that specifically handles foreign vehicles. My only hangup is that any major repair to that vehicle has cost big $$.

BTW, thanks for the link - I'm thrilled to get all the help I can (if only I had been a mechanic in a previous life!).