Stage 1 XUD, overheating a bit?

[johnny625]

Hi everybody,


I am having an issue with my XUD engined Cit Xsara. DHY engine, at 150k miles (245 k KM), lucas pump and KKK K03 turbo. 
I had done a stage 1 tune to it. It runs great, as much power as you can expect. About 180 degrees on the max fuel screw. The boost compensation screw fully in, then two turns out. The waste-gate screws adjusted to the end of the threaded bit on the K03. No smoke on boost (or a really light haze) that can only see in the headlights of cars behind me, 

Boosts to 19 psi on a really hard pull but to be honest I rarely push the car that hard. I do have mechanical sympathy and I do want to keep it reliable as at the moment is my only vehicle. 

Now I live in south eastern Europe as you might expect temps in the summer can be quite high. Few days ago while climbing a moderate but a fairly long hill in with the AC on the engine temp kept rising, it reached 100 *C and then 105 *C after which I parked on the side and allowed for the engine to cool down a bit. Both fans were on high, then when the engine cooled down a bit they switched to low speed. The rad is new, changed about a year ago, the same goes for the water pump. No low coolant levels, the car doesn't loose coolant what so ever. 

Now granted the AC was on, there were three people in the cars and I was maintaining a fairly high speed up the hill (80 to 85 kph) but still is this engine temp to be expected with a stage 1 tuned xud? 

I kind of worried of head gasket damage.

[JTaylor2005]

Xud's are known to run hot anyway aren't they? I bet going up hill at that speed with that much weight in temps like that and with a tune on it pushing more boost it'd probably get pretty warm!
Do you have a front mount intercooler on the car? Having one of those fitted would dramatically lower the intake temps and help keep the engine cooler

[johnny625]

Unfortunately still running on the stock top mounted inter cooler. I guess the additional boost and fuel does make the engine run hotter especially when climbing hills.

I do remember that before the stage 1 tune, the engine ran at most at 90 to 92 degrees when climbing hills in the summer but not nearly having the poke it has now, lol

[Dave]

Check the radiator. I have pulled several before and the fins between the passage galleries of the radiator literally fell apart and were completely packed/rusted not allowing good airflow.

I have confident this make a difference.

[johnny625]

I will do check the radiator even though it is rather new, only a year old.

Also I do plan to do a cooling system flush. Actually the coolant looks very fresh and the car apparently has been taken good care of in the past. Nevertheless I will do a flush just to see what effect it will have.

Also I have noticed that during night time when the ambient temps are lower, no amount of ragging can bring the temp higher than about 90 degrees. The thermostat is working as it should. Initially the top radiator hose is cold and then suddenly gets hot.

[Biggen]

May be you can add a oil cooler with a thermostatic plate to 92°

[johnny625]

Thank you to all for your suggestions.

It appears that I have solved at least part of the overheating problem. It all started when I noticed that the temp dial went up slightly when I turned on the headlights. Similarly turning any accessories on pushed the temp even higher unreasonably fast like in two secs.

I assumed that there is no way that the engine temp will rise so quickly with the engine idling. I thought that this must be something electrical in nature, possibly a grounding issue.

So I took the negative terminal cable of the battery and of the chassis leg and the gearbox. I gave it a good clean and added some solder to the terminals just to be sure. On top of this I added additional ground wires to the strut turret and to the thermostat housing near the blue temp gauge sensor.

The result is the engine temp seems to be lower now and it does not rise with any accessories being turned on. I still haven't booted the car properly (in hot weather, up a hill with the ac on) but I have a feeling that the temps will be lower now.

[johnny625]

OK now a bit of an update. I finally had an opportunity to test (rag ;d) the car properly. It was in similar weather on a similar hill with a similar amount of weight in the car. Now it only goes to about 97 *C after which the fans go from low to high speed and bring the temp down rapidly.

Now with the cooling issues seemingly sorted I started having some nagging thoughts in my mind which would not give me peace. These thoughts seeming consisted of sticking a 4 mill allen key in the Lucas and turning a certain screw inside even more in a clockwise direction.    

Unable to resist, I did it today. The surprising result, no increase in boost pressure although the turbo seems to boost up slightly faster than before. There is definite increase in fueling I can just feel it and see it by the amount of off boost smoke. 

Now is it possible that even with the waste gate arm on the k03 fully winded I can only boost to 19 psi despite the increase in fueling?

I started to look for boost leaks though nothing obvious. The D seal looks fine, no broken hoses or clamps, the turbo seems fine, only minimal amount of oil in the inter cooler, more like a slight oil film the coats the inside of it.