Hello,

Irecently bought a used 2003 S40 and for the most part, I love the car. This is in spite of a $400 front brake job and a faulty hazard light switch,a$135,all in the first week of ownership. We've had the car about a month now, and the mornings have been pretty cold - between 30 and 45 degrees F. I recently noticed that it has been idling very loudly when we are warming it up (sounds like a diesel truck), and the idle feels pretty rough. Also, there is a noise that I can only think to describe as a repetitive "thwapping" sound,sort of like the noise a piece of cloth makes if it is tied to a fan blade and hits on every rotation. Does that make sense? Anwyay, the sound and the idle are worse when the car is in reverse. The engine rpms remain steady with this problem.

Any ideas what could be wrong, and what it might cost to have it repaired?

BTW, I am a total noob, so if I have left out any pertinent information, let me know.

Thanks!

Keilah

 

You will need to pinpoint that noise. I'd suggest opening the hood and listening where the noise is coming from when you start it up. If it only happens when cold but slowly goes away as the engines warms it may be just a simple exhaust manifold leak. I had a nut back off the exhaust manifold down by the turbo. With the engine cold you can lean over the engine and use a light to see if one of your manifold nuts has backed off the stud. You might need to feel around back there to check each nut. Just make sure the engine is cold first.

This is a picture of the newer 5 cylinder exhaust manifold. Ours is similar. You can see the holes where the studs go through. The nuts would hold it tight against the engine.

 

I also bougth a used S40 2.0T (1999), with 50.000km.

And the car have the same problem at +/- 55.000km.
Not only with the engine cold, but always. Sometime do that more, sometime less.
And I started to feel some vibration too. Seems like a diesel car....

I went to volvo maintenence at 52.000km, the car were ok at time and they did'nt find nothing wrong with the car.
But they told me that they didn't replace the spark plug's, because they haven't the new model. (this is Portugal)
I think, maybe, the sparks are the same when the car was new....

Somebody tell me if the problem can be, most likely, the sparks or anything else

Thanks and sorry about my english [:-]

 

I listened to the noise again and these are the things I've noticed....

- more of a puffing sound, could be air coming from the exhaust manifold... but would that beoriginatingfrom the engine, passenger side? Cause that's where the sound is coming from.

- the noise is not as noticeable in park but gets quite loud when the car is put in drive, andeven worse in reverse

- noise becomes much less noticeable after car warms up

Does this help?

 

Did you ever find a solution to this problem? I have the exact same issue. I've cleaned the TB some but still same issue. Car runs awesome in warm but below mid-30's it sounds like a dumptruck and my gas mileage goes down.

 

How are your engine mounts? This can possibly effect your cars engine performance and mileage?

 

Sorry for the long overdue update but I just came back to the site for another issue and I realized I never posted my solution. It was loose/missing bolts on the exhaust manifold. The dealer said one was missing altogether and the rest were loose. So it's much better now.

The dealer did say that it is labor intensive to get them, whereas another poster seemed to indicate that it was easy to get to, so I may have been overcharged, but it cost $250 to fix - almost all labor.

 

Engine mounts aren't going to affect engine performance in a noticeable way, nor will they affect the mileage. If they are worn out you will get vibration at idle as well as a "rocking" when you shift into drive, reverse, etc.

 

Had this car for about 5 years now, and it has a gremlin in the engine management control including the sensors, actuators, valves and the like.

Anyway I have replaced the MAF - air flow sensor, now I am looking at replacing the Idle Control Valve, but I think its a petrol related issue with possibly the fuel pump but more likely the fuel pressure regulation and recirculation of fuel to the petrol tank.

They are good cars but there is a lot of hoses, esp' on the Turbo models, and not much room to work in / see whats going on. I suspect a leaky hose!

If only I had a hoist.

Also, if anyone in Australia is looking for reasonably priced Volvo parts I can probably point you in the right direction. Just remember all care no responsibility thing OK.

They are a real pain when they break down and I think i know more about my s40 than my mechanic. That's not saying much i guess.

That's all for now!

 

engine mounts do just that, mount the engine, nothing to do with much else apart from give your motor a good jolting if they are faulty. Typically there are 4 mounts, one one each side of the 'rectangular' motor. THe radiator and firewall side mounts on the s40 circa 2000 (and this doesn't change v often) are under the motor sitting on a cross member running down the centre of the engine bay. The passenger and driver side engine mounts can be seen from the top of the engine bay ie under the hood / bonnet. If they are 'cracked' you will hear metallic knocking sounds esp' over bumps / bumpy roads ... enough on 4 rubberized engine mounts.