Alfa Romeo Forums banner

Strange engine temperature behavior

912 views 12 replies 7 participants last post by  levp 
#1 ·
Gents,

Now that I have idle issues mostly sorted out, I've got another issue to take care of.

After a few dozens km on highway the engine temperature starts to climb into 220F/105C area. Usually my commute ends by then, so I don't know if it would go up any further. Now, if only left to idle, the engine temp is fine. I've also noted that it seems like temp goes up faster if I drive with higher rpm.

My car has an original AC heat exchanger mounted in front of the radiator, but I keep the AC off - the compressor is disconnected. So theoretically it could be that the heat exchanger disturbs airflow, but I've got a couple of friends with similar Spiders and they don't experience such high temperatures while driving.

I did full radiator cleaning about 800 miles ago (the car was parked for 12 years before that) and after that I've flushed the cooling system about 3 times, last time using dishwasher descaler.

Ideas on what could cause such behavior?
 
#2 ·
First verify the temperature with an infrared thermometer - your temperature gauge could be inaccurate.
If you have a mechanical, engine driven fan then the shroud must be in place.
Make sure that the exterior of the radiator is clean - no dried mud or oily grunge on the fins.
Verify that the drive belt for the water pump and alternator is in not slipping at higher rpm.

If it is none of those then you may have to have the inside of the radiator professionally cleaned.
 
#6 ·
Verify that the drive belt for the water pump and alternator is in not slipping at higher rpm.
How do I do that? The belt is one year old, tension seems fine. Other than that - I think I'll remove the radiator and will take to cleaning.

I did all the rest that you guys wrote about: verify the temperature with infrared thermometer, checked that radiator is clean from the outside, bled the system. Thermostat is new, one year old.
 
#3 ·
If the temperature is fine at idle, it does not sound like the fan or the shroud. What year is your car?
The sending unit and/or gauge could be the issue. Like in the previous response, a verification that the temperature is real is always a good idea.
You did not mention changing the thermostat or I missed that but i assume you did so. Don't really see that as the issue since it isn't hot at idle.
If it gets hot after a trip, will it then cool back down if left to idle or do you see it normal at idle only before driving?
Did you replace all of the hoses? I have seen them get de-laminated and look good on the outside but act as a restriction on the inside.
 
#7 ·
If it gets hot after a trip, will it then cool back down if left to idle or do you see it normal at idle only before driving?
Did you replace all of the hoses? I have seen them get de-laminated and look good on the outside but act as a restriction on the inside.
Actually, I haven't checked what would happen if I would leave to idle at high temperature.
I haven't replaced the radiator hoses, but they appear to be fine. Used, but without any build-ups.

I tend to think that my radiator is clogged and needs to be opened and cleaned with a rod or whatever it's called.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top