2.0 16v Rough Idle and start when warm

[omn0 0]

Hi sorry I know this is probably common and ive read about it in other forums but could do with a bit of help if possible !,

 

Owned the car for about a month and runs really well in general and starts up fine from cold- however after the car has warmed up (about 10-15 mins) the idle starts to become quite rough with revs fluctuating around the 750rpm mark. On a couple of occasions ive had a few misfires but they don't happen that consistently, and after stopping it can take about 4-6 seconds on the starter before re-spluttering into life. Also the engine seems to be running very warm (even after 10 minutes driving) although i know this is common with corrados. The bonnet is almost too hot to touch and the coolant temp is reading around the 110 degree mark. The oil temperature isn't reading anything at all on the MFA which i'm guessing may be something to do with it but not sure

 

I've changed the spark plugs, ht leads, air filter etc but im a bit of a newbie and could do with any technical suggestions- I've checked for air leaks but can't seem to find anything and the ISV was recently replaced by the previous owner, was thinking of giving it a bit of a clean anyway but any suggestions would be most apprectiated!

 

Thanks again,

[Stevo-M 0]

My supra has a similar problem so my mate who's a mechanic checked the head gasket and it's a gonner! He had a wee thing with blue liquid in it which screwed onto the radiator cap and within seconds the liquid turned green, indicating exhaust fumes escaping into the coolant. Might be worth getting it checked out...

[redwoodkp 0]

My head gasket was on the way out before christmas the car ran at 100 everywhere and crept upwards to 110 if in traffic etc. Had the head done now and re-skimmed and it never goes over 90. Are you constantly topping up the coolant??

 

Also make sure the fan comes on the when gettin hot especially if your car is running 110. New fan switch or even a small leak in the system can make the car run hotter. I had the head done, metal coolant pipe and oil cooler changed and still had a small leak from the radiator bottom corner which made the car run at 95 till the fan kicked in.

 

As for the idling issue make sure the idle valve on is the right one for the car if not you may need to tweek the idle screw on the throttle body. Not sure about the 2ltr valvers as I have an early valver but the temp sensor for the idle valve can cause idling issues especially from cold starting.

 

Well worth getting the head checked out first and any leaks from the coolant system to establish why its running hot then it may sort out the idling of the car.

 

Hope this helps :)

[omn0 0]

Cheers for the comments!

 

funny you should mention the gasket problems, yesterday when i started it there was an alarming bang and loss of power..... Figured it might be to do with the gasket, although when i checked the engine I found i had blown the breather hose and Sticking some new jubilee clips on it seemed to solve the problem.

 

Don't think its entirely fixed as it was misfiring today and can still take a bit of a while to start up, but the breather hose might have been something to do with the overheating. The coolant is clear and the level is ok which might suggest the gasket is ok but its going in for a service as looks like it hasnt had one in a few years so im hoping that this should pick up any major issues.

 

thanks again for your comments, have a worrying feeling that the gasket might be something to do with it but ill keep the progress posted.

[redwoodkp 0]

Cheers for the comments!

 

funny you should mention the gasket problems, yesterday when i started it there was an alarming bang and loss of power..... Figured it might be to do with the gasket, although when i checked the engine I found i had blown the breather hose and Sticking some new jubilee clips on it seemed to solve the problem.

 

Don't think its entirely fixed as it was misfiring today and can still take a bit of a while to start up, but the breather hose might have been something to do with the overheating. The coolant is clear and the level is ok which might suggest the gasket is ok but its going in for a service as looks like it hasnt had one in a few years so im hoping that this should pick up any major issues.

 

thanks again for your comments, have a worrying feeling that the gasket might be something to do with it but ill keep the progress posted.

 

If your not losing any coolant then your right it may not be the gasket but worth checking anyway. To blow the breather off must have had some pressure in the system though??

 

As far as starting problems go then any of the obvious apart from what you've already changed leads, plugs, dizzy cap, rotor arm, ignition coil, starter itself or even the ignition switch on the back of the key chamber these do burn out :shrug:

[mattkh 0]

...........its going in for a service

Hi

When they take the old plugs out, tell them to do a compression check.

[omn0 0]

hi cheers again for the suggestions- just a bit of an update,

 

well got it back from my mates garage, aside from a few small issues- seems to be the main cause was a dodgy fuel filter and a fried rotor arm as redwoodkp mentioned. It doesn't help that a previous owner has done a bit of a bodge job on the exhaust which makes the whole thing rattle at points- but got him to do a compression test and it seems everything is ok enginewise.

 

Think the bearings might need doing in one of the front wheels as theres a slight knocking noise, but as far as i can tell the idling/ starting issue has improved a lot.

 

Thanks again, and ill keep this updated,