Im going to try to explain everything in this post that I have done in the last couple months in which ive had this sporadic overheating problem. Ok, I bought an 87 mk3 with a rebuilt engine with 40 over pistons and arp studs, stock turbo, 3'' custom exhaust, hks MHG, pretty new core radiator, XS power fmic, NO thermostat, and everything else stock besides an electric fan. I bought and installed a 60 trim ct26 and started having overheating problems shortly after when on the highway for extended periods of time if I slowed down and got off an exit ramp. I bled the system thoroughly but it didnt do anything. I then realized that the previous owner had the relay wires wired wrong making it blow the wrong way. I thought for sure this solved my problem but sure enough it still overheated on cue when I got off the exit ramp after sitting still in traffic. Other than being on the highway, it NEVER overheated. A couple days later, it was overheating again on the highway so I pulled over and popped the hood. Literally 10 seconds later, the hose connecting to the heater valve popped off and all the coolant came out. I then considered that the bigger turbo needed more air so I bought a stock clutch fan and installed it that night. The next day, I turned the car on and I had smoke out of the exhaust and smoke/steam coming from the turbo where it connects to the exhaust and downpipe. The turbo was so hot it was glowing red... Anyways, could not having a thermostat be the problem? I recently disconnected the coolant lines and there was plenty of coolant getting in to the turbo. Or could my water pump be bad? After all, more problems did occur immediately after installing the clutch fan. Thanks again guys, your input is really appreciated.
Confusing Overheating problem for the last time
- Thread starter vpr131
- Start date
Have you checked your ignition timing? Your post is still a little unclear about when it actually overheats. In its current state, when does it overheat? On the highway, around town, or just after exiting the highway and idling? Are all the shrouds/engine under covers in place?
After it overheated, I had it tuned with the new turbo because the timing was off. And it has overheated both on the highway and after getting off the highway once there is traffic and I slow down. Generally, if Im on the highway for longer than 20-30 minutes, it will overheat very quickly. And yes, all shrouds are in place.
besides the shroud for the fan which i dont have because i got it locally from a friend.
besides the shroud for the fan which i dont have because i got it locally from a friend.
And im not sure the fan shroud would help that much. When i say its overheating, it gets around 3/4 of the way up on the stock gauge and Im sure it could have kept going up...
I had recent overheating issues...it was from running the car super rich and retarded timing. With a proper tune, it was fine. I had similar symptoms of overheating for longer rides on the highway etc.
Not to say this is the issue, I'm just relating to your situation/story.
Not to say this is the issue, I'm just relating to your situation/story.
hmmm i thought that running lean would make it overheat not running rich. I was initially running lean after I installed the turbo (i have an AEM wideband) but after being tuned, it is now running rich for engine safety since Im on 18 pounds.. But im not sure thats my problem because like i said, when it overheats, it doesnt overheat by 10*, it overheats by wayyy more than that
ah ok, im going to buy a thermostat tomorrow and see what happens. Maybe it wasnt a problem when i bought it in march because it wasnt that hot outside yet.. thanks
Fan shroud and under body panels can help a lot more with cooling than most people think. If you're having issues, it WILL make a difference. Whether it's enough I don't know. You're hurting your cooling capacity before you even get started without them in place.