20 Most Recent 2000 Volvo S40 - Page 4 Questions & Answers

An engine control unit (ECU), also known as power-train control module (PCM), or engine control module (ECM) is a type of electronic control unit that determines the amount of fuel, ignition timing and other parameters an internal combustion engine needs to keep running. It does this by reading values from multidimensional performance maps (so called LUTs), using input values (e.g. engine speed) calculated from signals coming from sensor devices monitoring the engine.

if this is an interference motor then it can cause engine damage to the valve train and pistons. check with the dealer or a shop that works on Volvos and ask if it is an interference motor.

Only way to assess the damages is to remove the head and check

It can sometimes depending on where the valve smacks the piston and what speed you are driving

Yes, and also bends valves

Your S40, I'm 90% sure, is an interference design, meaning if you don't change the timing belt every 100,000 miles and let it break, yes the engine is damaged. The valves will lock in an"interference position", so when the piston reaches top dead center, it hits the valve. You have a dead engine!

If it's a "clicking" sound, (metallic) that's usually bad. If it's less of a pronounced sound, it (could be) a valve sticking but that's being pretty optimistic.

are you sure its the head gasket? they can suffer with condensation. mine suffers from this during cold weather. if it does loose water likely to be that. taking head off bit of a pain. you need to support engine. remove auxcillary belt and timing belt some wiring water pipes manifolds top engine cam shaft head bolts

take it to a mechanic? inspect the belt. its bad. the FSM covers the steps. in USA we have alldata.com to do same, step by step.

never post emails on line, you now get spam for ever. endless... and bad news 2 , you cant delete it. and we dont sell cars here.

this is in the FSM book "factory service manual" and at alldata.com read them. later is on line for $15 . on most cars, we remove all that stuff attatched. wires ,cables, hoses. on some drain coolant. then UN BOLT IT. end story. for blow by blow step by step the FSM is the only book that does that. there are FSM clones, hit and miss. all books are clones of the real deal the FSM is the real deal. if you read the books they all have , markings. this drawing courtesy of volvo, on every page, see, its just a clone. my point, is some book butcher the facts. (chilt..... and Hayn....) they mix years. in a toxic soup of danger. we all them RAGS. or door stops. get the read FSM. (at the dealer, no less) or #2 , alldata.com read that and then ask good questions. RTM. it may just tell you, it's over your head or takes too much time. or lack tools or all 3. there is no other way , but to read and understand.

On the internet Google your motor & the question, for a picture

I would have the throttle plate cleaned because when they get dirty they have the symptoms that you are describing

Yes, and no. The timing belt MUST BE CHANGED. It should have been changed at around 60,000miles Bad, bad things can happen if it breaks while its running. As for the tranny fluid, it has probably never been changed either so it's probably 11 years old. Just have that changed as well. Otherwise, very nice car. Good luck with it.