Hello Guys,

I recently aquired a decent shaped Accord 5SPD 1993 LX with 170K. Car runs like new. However, when I am stuck in traffic for say around 15-20 mins, the engine Idling RPM keeps increasing. It gets to around 2500rpm and stays there. This overheats the motor - does not reach the red line, but reaches close to it. I did some google search to figure out what might be the issue, but have found no answer.

Has anybody else encountered this? I love the car, but in rush hour traffic, this is a huge annoyance and extremely worrysome. Please help me out... I just need to know what part needs replacement.

 

your thinking that the rising rpm is making the engine overheat, and i think that the engine overheating could be causing the rise in your rpm. there are coolant tubes that run to the throttle body. i think you should check the cooling system first. is the level correct? maybe the coolant is really old and needs to be changed out and flushed. pull the spark plugs and take a look at the end, do you see any white deposits?

 

Hmm, Wow never thought of that. Coolant level is ok, but it could be old. I will replace the engine coolant and will also inspect the spark plugs and will get back to you guys.

So you don't think it could be a spring or valve that is getting stuck?

One thing I forgot to mention is that, the rpm rises progressively, say 1K, 1.5K, 2K and then finally to 2.5K. As soon as the road clears up and I get to drive the car, engine starts cooling down and the rpm issue goes away. That makes me think that your diagnosis is correct. I will report back ASAP.

Thanks a lot.

 

also make sure that BOTH fans are working ..........also chk to make sure that the throttle blade is not all gummed up and sticking

 

Desert, thanks for your post. I don't however know what you mean by the throttle blade. Are you talking about the metal part which is connected to the accelaration cable?

 

throttle blade aka butterfly, basically you have to take the intake tubing off of the throttle body to find out its specifically the piece that moves inside the throttle body when the throttle cable is pulled back

 

very good marbro and thanks for a very good explanation........

But yes...... throttle blades sometimes they get gummed up and stick.. . just like Marbro said, pull the tube back, get a can of carb cleaner, get a rag, spray carb cleaner on the rag. hold the blade open and clean all around the area where the blade would open and close ..

 

Hey marbro and desert, thanks for the suggestions. I will most likely not get a chance to open up the car before the weekend. I guess I will drive my $375 Prizm until then.

 

I got the coolent flushed and checked the spark plugs. The spark plugs didnt seem to have any white deposit. However 3 out of the 4 spark plug wells had oil leak!!! I guess I will need to get the o-rings replaced - probably with the timing belt.

Car does not seem overheat anymore and also I don't notice the idling rising anymore. Both cooling fans seem to be working.

Thanks a lot for the suggestions guys.

 

replace your t-stat. it may be sticking causing your problems