S40: Time to scrap it?

[ukpaul]

Hi everyone first post here from a long time lurker in the UK.

I have a 2000 Volvo S40 with the 1.6 engine that's done 110000 miles. Always been a reliable car until this year. In July of this year I started getting the dreaded brrr brrr brrr VVT rattle when the car was ticking over that seemed to get worse pretty quickly, the cambelt on the car was changed at 85000. Got a few quotes for having this done which were coming in at about £500 at an independent Volvo specialist. As the car appears to only be worth about £500 - £600 at best looking around various "for sale" sites even though it really is in A1 condition I decided to leave it for a bit.

As the VVT pulley got noisy very quickly I just unplugged the power to the solenoid as a temporary solution which stopped the noise and didn't really seem to effect the car except possibly a slight loss of power at high speeds.

All well and good until a few days ago. Started the car as normal everything seemed fine until it warmed up, then suddenly whilst I was about to pull out of a junction the car decided to rev itself to 4000 rpm and stick there! I pulled into the side of the road and cut the engine out, tried to get it started again which was a bit of a task as it didn't want to start for some reason.

Eventually it did start and when it did the tickover was normal at about 800 rpm, as soon as I pulled off the revs went straight back up to 4000 rpm and stayed there. I drove the car home like that! Even though it was driving itself really. Occasionally the revs would try and drop off to normal but they would then just come straight back up to 4000 rpm.

I got the car home and just left it on the drive and went back out in my other car. I have tried to start the s40 a couple of times since from cold and the tickover has been fine so this appears to be something that's happening as soon as the car reaches normal operating temperature.

Has anyone got any ideas if this could be related to the VVT pulley solenoid being disconnected? Or would this more than likely be something else that's gone wrong with it? It appears to be the older model with the accelerator cable as I read a few problems with the newer models with the electronic unit.

Thanks for any help that anyone can give me.

[beat106]

sounds like air flow mass unit or lamba sensor , best on a computer to be 100% sure .or ELM327 & smart phone & obd car doctor

[phil_r]

When me old car did this I had the fault codes read (EML light was on some of the time) and showed up as engine temp sensor. Changed and problem solved!

Was less than £30 for a genuine sensor from volvo, easy to fit. Drain some of the coolant (when the engine is cool) from the bottom radiator tap, undo the thermostat housing, 2 torx bolts if i remember correct, then unscrew the sensor. I would also fit a new genuine thermostat if the temp needle doesn't sit at exactly half way, cheap and easy to do at the same time, I went from a 34mpg average to 37mpg!

I gambled with the VVT, I decided not to have it done and must of covered well in excess of 30k miles with the issue. The car got taken of the road when it failed its MOT, it needed front to rear brake pipes, one rear brake caliper and cambelt was due. Far more than a 186k mile car which was worth and I had already bought a newer, faster, nicer, more efficent replacement!

Phil

[volvorocks]

Originally Posted by ukpaul

It appears to be the older model with the accelerator cable as I read a few problems with the newer models with the electronic unit.

Thanks for any help that anyone can give me.

Just a wild stab in the dark, but if its got a cable, could it be sticking?

I had a BX that did the opposite - it wouldn't rev beyond about 3500 to 4000, and it turned out to be the accelerator cable that was twisted.

Regards

[jasedarace]

I dont know about VVT engined cars but check your vacuum hose that goes to the throttle housing. When mine did this, thats what it was. I couldn't see it immediately due to being hidden by other wires. With a leak, the lambda sensor thinks there is too much O2 (well, I guess there would be) and so increases revs to compensate.

[ukpaul]

Thanks for all the replies, after some investigating tonight I've found the problem although not yet found the source of the problem. When the engine is getting warm petrol is leaking out from somewhere! You can hear it (and smell it) keep hissing as if it's hitting something warm, it would probably explain why the car has suddenly become so awkward to start as well. It took that long to get it started that it nearly flattened the battery, it's never done anything like that before. I could also smell the petrol on it tonight as well once that hissing noise started. Looks like it was a good job I brought it home the other day and didn't carry on driving it!

Will investigate further tomorrow and try to find out where it's leaking from and update you all, once again thanks for taking the time to reply :-)

[ukpaul]

Oh well after investigating the problem me and the car have now parted company :-(
The fuel was leaking at the top of the fuel pipe just where the pipe goes into the throttle body housing. The fitting there was all loose, I did have a quick look to see if it could be tightened and as I tried it the whole fitting then came away completely! So faced with that I decided it was time to let the car go so it's been sold this afternoon as spares or repairs via a local for sale website :-(

Still one good thing, it now gives me a good excuse to try a diesel S40 that I've always wanted! It's just a matter of finding one without starship mileage now ;-)