Very hot K series

[Andrew Dent]

Here is the story so far.

 

At the Club day at Oulton Park, my engine decided to spill some coolant, event thought the water temp was looking ok. As a precaution, I took the head off and had a look for any damage. Head gasket was OK and the head has been pressure tested and no problem found.

 

On the rebuild, I took the heater out of the circuit and plumbed the feed from the top water rail to the thermostat housing as in the build manual.

 

I have now bled the engine twice and now get a very hot running engine very quickly. Looking at 90 plus deg after 3 miles. Previously the engine always ran at 80 deg and the ecu controlled fan comes on at 90 deg. It was very unusual for it to come on in such a short time.

 

Even tried blowing into the header tank and flushing through fluid/bubbles. Thought that had worked whilst running in the garage.

 

Also tried taking the pipe off the water rail and making sure it is full at that point.

 

I know the thermostat is working as I tested it when the head was off.

 

Now looking for ideas or suggestions as Im at Oulton with Slipstream on Wednesday, and in current form, its not looking good.

 

The engine is in a SLR

 

Andrew

[F355GTS]

Andrew

 

I have exactly the same problem and was just about to post the same question! on and SLR as well

 

I've just replaced the Head Gasket and Head Bolts as there appeared to be some water in the oil and it was unclear whether the previous owner had had it resolved and it was leftover or genuinely leaking.

 

I'm at Silverstone tomorrow and I can't stop the temps going to 100+ even with the fan running permanently.

 

I've tried bleeding the system in the same way as you about 10 times, had the front of the car in the air to get the expansion tank as high as possible

 

COULD THE HEAD GASKET STILL NOT BE SEALING AND CAUSE THIS PROBLEM?

 

If anybody has any brilliant ideas I'd be grateful for a call on 07831 662630 as I don't really want to do Silverstone GP circuit in my Beemer!

 

Mark

[Allen Payne]

It sounds like you still have an air lock.

 

Have you both definitely got water flowing through the radiator, i.e. is the bottom hose from the radiator hot?

 

Silly question but are you bleeding the air out of the system via the bleed nut on the radiator, with the engine running and the expansion bottle cap off?

 

Is the fan coming on as normal?

 

Regards

Allen

 

[F355GTS]

Allen

 

for my part the rad is hot, both hoses are hot and no thermostat is fitted, It happen if I short the fan to run permanently or leave the (new) fan switch to make it run

 

 

 

Mark

[Andrew Dent]

Allen

 

Bottom hose gets hot without problem. Emerald fan set to come on at 90, and does without problem.

 

Also get trickle of water into teh top of the expansion tank from teh TB pipe.

 

Been running the car wth the nose well up in teh air with hte expansion cap off, and regularly checking teh bleed srew. all teh silicon pipes are given a regular squeeze.

 

Need to sort this out as Ive seen teh entry list for Oulton.

 

Edited by - Andrew Dent on 28 Jul 2002 20:57:11

[Gridgway]

it's not unklnown for the temp sensors to be completely up the duff. My (Stack) water temp sensor went potty recently and was reading 300 degrees. When it first started failing I thought the water temp had shot up very quickly from cold.

 

If you have an oil temp sensor yo can swap the two to see what happens. Or put the water one in a kettle and see if it reads 100 on boiling, or ages before.

 

Graham

[R500 CYA]

Mark,

 

You have mail,

 

Nick

[Andrew Dent]

Graham

 

THe water temp on the gague and the water temp shown on the laptop through the ECU are quite close.

[Rob Walker]

Andrew I second Grahams advise, if the sensor is duff it won`t matter what you read its resistance with it will read incorrectly. I advise you also to check on the wiring connection to the temp sensor in the water rail and solder the spade connector on if possible. I have experienced silly readings and this was due to a high resistance crimped spade connector.

 

See you at Oulton

 

Rob

[murph7355]

Is it stable at 90? Is the fan always on? If you set the fan to come on higher, does the engine run correspondingly higher temps?

 

Might be worth having another look at the thermostat to see what temp it's opening at, but then if it's not opening, doesn't that mean that the rad is being bypassed and that the fan would therefore have no effect? If it's stuck open it should run cooler to a point.

 

If it makes you feel better mine's also started "playing up" in the last few days temps wise, getting hotter quicker in traffic. The fan seems to bring it under control (now it's kind of working after a temporary work around on Le Sept! Now *that's* a very wierd problem) but it didn't do it before so not sure what's occurring there. It's fine when on the move so I'm starting to think it's just hotter than usual ambients, which could easily be 5-10degC higher than the car's been used to off late...then again I'm not sure such a rise would affect it like that...

[Andrew Dent]

Rob

 

2 individual sensors. 1 drives the temp gague, the other is for the ECU, and both read close to each other.

 

Edited by - Andrew Dent on 29 Jul 2002 11:11:28

[Johnty Lyons]

Slight confusion here, number of points ecu and temp guage see two different sensors and the small single one at the end of the club foot, is a known problem , it gets loose in its housing, the connection goes intermittent high, plus the guage is not reliable.

Running without a thermostat at all is not a good idea in any car, a certain level of resistance is necessary in the K water ccirc system.

The coolant itself is important do not use water in a K use either the Rover 4year summer coolant NEAT or the Comma equivalent so not use any other mix, A bottle of water wetter will help heat transfer from the cyl head to the coolant and conversly from the coolant to the radiator finns.

Sometimes in the K series on cold days the car can over heat this is due to the thermostat seeing cold water from the radiator and not the hot from the engine if this is a problem it can be over come by blanking off a small portion of the bottom of the Rad. Generally K's will run OK if for track use if you have the large alloy rad and the fan controlled from the ECU, not the switch on the rad, and of course the right coolant. Be very very carefull if you have the head off not to move the reciprocating bits at all as you will break the seal at the liner/block interface.and then your F****D.

Have fun!

 

jj

N.I. L7C AO.

Membership No.3927.

[Marius]

Had a similiar problem with my VX. The pipe carrying hot water from the head runs normaly into the heater, cools down there (well at least a little) and returns back to the main water rail which leads to the water-pump going into the block again. Simple here (even no one could tell me at the time): if you disconnect the heater, the hot water from the head returns uncooled into the water-rail which normally carries cold water being pumped into the block. I also had temps around 100°C all the time. One day I just closed the head on the heater-hot-water-exit and also locked the counterpart of the water-rail. Voila, 85°C, no matter how hard you push it. Maybe the K-series coolant circuit is similiar, don´t know.

 

Hope this helps a little.

 

Marius

 

 

[Andrew Dent]

Found and fixed it.

 

Decided to check out the thermostat again. Took it out and noticed it was not in the correct way round. 😳Tried things out without the stat in and all working. . So I can go teh the track day on Wednesday after all.

 

Just need to clean it up and pick up the trailer.

 

Thanks for all the input from all and sundry.