Hi guys

I have3 questions.

1. Whenever I add a little water to my 2000 cl600 coolant tank, i get the car going into limp mode after 10 mins of driving. I will stop the car,
turn it off, then back on and I will be away with no other problems. Any ideas?

2. When I start the car in the morning, there is a very rough idle. I then put the car into R and can feel the vibration through the steering wheel. It is very rough. Once in D the vibration is less, untill the car is at 100 degrees c. Then it runs very well, with no vribration. Any ideas?

3. What is the correct running temp on this vehicle. On the freeway, it runs at 80 degrees, but in town it gets up to 100 degrees. I do not drive the car hard, and have never had a car that has a temp variation while driving. Is this normal that there is movement between 80 and 100 degrees?

 

Hi,

So how much, how often are you adding water? The system is sealed and in principle should not need topping up. Are you filling to the correct mark on level ground?

If indeed the car is using water then it looks like you have a leak with the rough idle indicating a head gasket.

Come back with some answers and i will see if I can help further.

Stuart

 

I only have to add some water once every 2 to 3 months. Very little though. I had the oil cooler replaced in February and replaced all the gaskets then. The car runs like a dream when it is warm though.

 

Hi,

Whenever I add a little water to my 2000 cl600 coolant tank, i get the car going into limp mode after 10 mins of driving. I will stop the car,
turn it off, then back on and I will be away with no other problems.

Is this totally repeatable on demand?

Does the CEL Check Engine Light come on with Limp Home? If so try to get the codes read BEFORE you turn the ignition off.

I suspect that the ECU is sensing a misfire (codes will confirm) and therefore going to Limp. Issue is what causes the misfire which is why I ask the first question regarding repeatablity. If you just pretend to add water i.e. remove filler cap BUT add no water..what happens then? Sure you are filling to the correct level?

Stuart

 

It is repeatable on demand.

No light comes on. I have noticed a misfire now and again. The car almost loses all revs, has a shudder and goes into limp mode. This will mostly happen in traffic.

I will try removing the cap and reproducing the problem. Many thanks.

 

So...
Test 1.
Does it happen when you "top up" but add no water.
Test2.
What happens if you "top up" but leave the cap off.
Note: Keep a watch on your temp guage when doing this in order to make sure water isn't ejected fro the header tank or the engine overheats etc. Shouldn't be a problem BUT you never know.

I suspect that these tests will point to a head gasket problem. Basically the cooling system pressure goes up and finds a way out (into the cylinders) prior to the pressure being released by the radiator pressure cap. Water in cylinder = Misfire = Limp Home.
However, lets wait and see what your results give us.If I'm correct I don't understand why a quick restart clears the problem since the pressure will not have been reduced because the engine will not have cooled and you have no CEL.

Mmm.