156 2.4jtd overheating -but why?
Hello, I have tried searching for related threads, but so far haven't been able to find any answers. So I am hoping someone may be able to offer an opinion on my problem. Here is the history up to now:
During winter, no overheating issues noticed.
During Summer, when on motorways, I cannot get above 70 without overheating. Local trips no problem, but yesterday’s trip to Wales and back was not enjoyable. I had to de-clutch on the down slopes so I could get the engine cool enough to make it up the next slope. Even doing 50mph on a gentle upwards slope was enough to start the needle's steady, but determined crawl towards the 3/4 mark.
Fans are cutting in just before needle reaches 3/4 mark on temp gauge, and they do cool the engine quite quickly if the car is standing still. So I believe water pump, thermostat & radiator(?) are okay.
2 different thermostats tried -same symptoms- & I did have the car looked at last Autumn by a local reliable garage. They could not find a clear fault. Water pump tested good by them (and it is less than 2 years old anyhow). Cooling system flushed, but fault persists.
ECU re-tuned by Angel Tuning a couple of years ago, so engine could be expected to produce a bit more heat, but not by the extremely tame way it has to be driven right now.
The radiator looks okay, but I may need a closer look. The local garage thought it was alright when they looked at it last October. Now it is Summer again, and I have been on the motorway, then the problem rears its ugly head again. I notice that some of the lower fins are bent on the radiator, which will restrict the airflow a bit, but this is only on the lower part of the radiator. Higher up they look fine.
I am wondering if there could be an issue with the oil cooler? I'm not sure which direction to go in here. Any ideas?