Another K-Series Cooling Problem (S2 111s)

[Alex 111s]

I had an interesting drive into work this morning where the temperature on the stack display was fluctuating wildly & since reading up on John Reid's threads on cooling problems was really starting to brick myself.

In the short time i've had the car (Dec '07) the running temp and stationary temps have always been pretty stable (running @ 88 deg.C & stationary @ 93 and rarely heard the rad fan come on). Since having it serviced last month, I've noticed the temperature becoming less stable. over the last couple of drives the rate of rise & fall became more pronounced until this morning it was swinging sharply between high 80's to peaks of 112 deg.C and then back down again. I pulled over but by that time the temp had dropped again and checked the level in the expansion tank which was fine & continued into work, the temperature continued to fluctuate the rest of the way. Temperature was at it's most stable when at cruising speeds on the dual-carraigeway (3500 rpm). As soon as i got to work, I checked the expansion tank again and cracked open the cap slightly. Big release of air and the expansion tank surged full. Took cap fully off to allow remainder of trapped air to be vented and replaced cap with level in the expansion tank close to top.

Went back to it at lunchtime to check how things were. Expansion tank now fully empty and no sign of leaks or anti-freeze residue anywhere. So topped up the reservoir and ran it for a good 30 mins mostly at idle but sometimes at 1/2 throttle. temperature stayed constant @ 93 deg.C and dropped down to 88 on 1/2 throttle so I think it's safe enought to drive home.
I can only think that the garage hadn't fully bled/filled the system when they did the coolant change at the service.

Is there any other special tricks to bleed the system? What should I keep an eye on for the next few miles?
Would a temp spike of 112 deg.C do major harm the the engine?

Cheers

Alex

[Rich H]

112 is ok briefly, but the temp gauges are wildly variable in their accuracy.

You need to bleed from the front left rad hose with the car up to temp and preferably parked with front left corner highest. Wear gloves though its hot and pressureised! there is a slot in the bleed screw so you only have to loosen it.

Fluctuating temp could be air lock, HGF or just a temp sender on its way out, start with bleeding it then chege the coolant sensor then get a block sniff done. Also replace the expansion tank cap to ensure its not venting and causing the coolant to depresurise.

When you open the coolant tank you release the pressure and the hot bits of the engine will boil the coolant instantly, also the gas you release is coolant vapour so you will loose some coolant if you do this. So just don't ok

[tenkfeet]

I had some trapped air in mine, no temperature variations just big coolant changes . Found leaving the cap off overnight filling to min leaving it off and running till its was hot as you do when filling stabilised things .

As rich says do a bleed . This may help http://wiki.seloc.org/a/Bleed_the_cooling_system

[Alex 111s]

Two thinghs.
1)
Were should the radiator bleed on the s2 111s be because it's not in the outlet pipe from the rad to the solid tubing at the chassis as per the workshop manual??

2)
Couldn't bleed as per jacking up front pax side and bleeding off (see above) so jacked up pax rear to as high as possible and opened the bleed on the cooling return line on the LHS of the engine. constanst stream of coolant coming out, no trapped air. ran it for at least an hour whilst jacked up & it warmed up and went through it's cycle as should do. (rad outlet was hot to touch but not unbearable & fan was kicking in to do it's job too.)

this morning it overheated and boiled on the way into work. (temp was showing 114 degC on the stack)

temperature rocketed as i was going up hill but not giving it too much of a ragging. parked up to let it cool (with nose downhill.) the rad wasn't giving off too much heat and the outlet was cold. so from that I'm guessing that it's HGF and it boils because the gases are vapour locking the radiator when i go up hill.

off to the garage for me.

[BiggestNizzy]

AA parts and Labour ?

[Alex 111s]

No, hindsight's a great thing.

[BiggestNizzy]

Wouldn't it be a shame if you had this thread deleted took it out for future use the car was magically ok for 3 weeks* then it was to re-occure on a trip to Ikea in edinburgh and it had to be towed to a garage/nearby specialist


*you don't want them to think there is something wrong with it

[robin]

If it overheats that easily, a block test (like a big pipette that sniffs the coolant in the expansion tank looking for signs of combustion gas) will reveal all quickly. I have access to one here in Edinburgh - Ali @ SLS has one too.

The bleed nipple is on the exit of the rad up behind the headlight - if you turn the wheel on full lock you'll see a grommet in the wheel arch liner (about 5" diameter) - you pop that out and you'll see the rad pipe behind it with the bleed nipple on top - DON'T DROP THE BLEED NIPPLE!!!!

Cheers,
Robin

[Alex 111s]

Well got the car back yesterday night - after 3 weeks in the garage. FFS.
It was HGF - Head was skimmed as it was a little out. (don't know how much they took off)
lets hope it holds together, for a wee while anyway.