seat leon revving

deaglan169

ive noticed recently my leon 2001 sdi on start up is revving up to 1500rpm and staying at 1500 for about 20secs then drops back to normal 900rpm, also the engine doesnt seem as responsive, i know an sdi aint exactly responsive.. but it didnt have the response i was used of, it has done this a few times but after about 5mins driving it settles back as normal, could it be a sensor problem

Muckymitts

I would start by cleaning the throttle body and see if that makes a difference to the high revs. Some VAG cars need the throttle body adaption settings done and this can solve the mentioned problem - this needs to be done with VAG software on a code reader.

If the car has not been serviced then you need to start at that point first or have the codes read to get more information of what is going on.

tossy

Coolant temp sensor would be my bet,the sensor goes faulty and throws a low reading so when you start the car it starts in 'cold start' mode which basically involves the ECU racing the engine slightly to get everything up to temp a little quicker.

deaglan169

thanks guys for your responses it was only serviced 6000 mile ago so that end should be ok, ill get it on the computer so and get the fault codes read. thanks again ive had the car nearly 4 years myself and the car is coming up on 10 years and this is its first throwing leg out of bed moment...

Muckymitts

tossy wrote: »

Coolant temp sensor would be my bet,the sensor goes faulty and throws a low reading so when you start the car it starts in 'cold start' mode which basically involves the ECU racing the engine slightly to get everything up to temp a little quicker.

This post has just reminded me that I had to replace a coolant temp sensor on a Leon a good few years back and symptoms were similar to this so this could very well be the cause. Best to read codes first rather than throw parts at it. Good luck, let us know how you get on.

deaglan169

hi guys need your help got replacement sensor, but when i went to pull out the old one (i had released the coolant pressure before hand) it gussed out everywere, from reading how-to's this shouldnt have happened i put old sensor back in asap so lost very little coolant but i dont know were to go from here

AzureAuto

No throttle body on Sdi. THe throttle looking yoke is a pressure actuated cut off valve to prevent dieseling when you stop the van. In my opinion a plug in diagnostic would be in order, but off the top of my head, air mass meters can cause similar probs, as well as the aformetioned coolant temp sensor and of course air leaks from inlet tracts. Whereabouts are you based, might eb able to pop out to you for a plug in?

CarMuppet

Air leak between manifold and air meter. Does car rev when you dip clutch to stop at traffic lights?

deaglan169

CarMuppet wrote: »

Air leak between manifold and air meter. Does car rev when you dip clutch to stop at traffic lights?

no it doesnt only when i restart car after it being warm, im getting a hand tomorrow changing coolant/temp sensor so will report back my findings

deaglan169

all done dusted and replaced not as bad i was thinking when done correct:rolleyes: seems to be running better on startup i hope that my mpg may also improve

CarMuppet

deaglan169 wrote: »

all done dusted and replaced not as bad i was thinking when done correct:rolleyes: seems to be running better on startup i hope that my mpg may also improve

Ah good result so... what was replaced in the end? Themo sensor?