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K series cooling problems

PostPosted: Mon Sep 08, 2014 10:02 pm
by Rich
I know it isn't a Midas, but it does have a K-series, albeit at the wrong end...... I've just posted this across on the GTM forum.

After a weeks ownership of the K3 I have sorted a lot of the little niggles and oddities out. The one bit I'm not having much luck with is the 'cooling' system which is causing me some stress. Please excuse the long post.

Basics first, this is a 1.4 K16 MPi engine with approximately 43000 on the clock, assuming it's the original engine. There's no evidence the engine has been apart, the thermostat arrangement is standard and there is a metro cross flow radiator up front. The gills on the radiator are pretty knackered looking directly behind the air intake, however the rest of the radiator appears fine.

The cooling problems are inconsistent, some days it will behave itself completely over say a 10 mile journey, other days it will overheat 4-5 miles in. Often the temp will drop to the middle of the gauge after raising which I assume is the cold water re-entering the engine when the thermostat opens. On longer, particularly higher speed runs this process repeats itself but with the cooler temperature being higher every cycle. Sometimes giving the engine a quick buzz with the clutch down seems to start the cooling phase off and quite often it will drop to normal.

Throughout all of this the engine runs smoothly without any funny noises or misses, there doesn't appear to be any water in the oil, the car isn't smoking (white or blue) and the car is returning around 35-40mpg. The interior heater doesn't go cold either and there's no bubbling in the expansion tank when the engine is running.

The first issue I found was that the cooling fans (Kenlowes pulling through the rad) weren't coming on, no matter what the temperature. For now I have got them running on a separate switch, though they don't appear to make any difference when the engine starts getting hot.

The second issue was the system wasn't pressurising, closer inspection found a snapped stub on the top of the expansion tank that someone has replaced with a bit of tube 'glued' in place with silicone sealant. As a temporary measure I have epoxied this in place which appears to have done the trick and the system now pressurises. I'm not sure, but I think the coolant level has dropped slightly now.


Obviously my concern is a goosed head gasket, though if it is, it is different to any other blown HG I've ever experienced. Next suspect is the pump, I understand these are pretty much a service item and at 40k it's probably due to be replaced. Do they loose pumping efficiency or do they just leak when they go?

I understand a remote or PRT system from an MGF/Freelander would be a good investment for the future, I assume neither is going to address the basic problems I'm describing?

I'm hoping I'm not the only one here who has had these problems, what I'm really hoping is that someone has found the solution.

Re: K series cooling problems

PostPosted: Tue Sep 09, 2014 7:28 am
by Hans Efde
I had this engine in my Rover 214 and on this car the pump failed by a major leak of the seal. Can't it be something simple like an intermittent sticking thermostat? Other idea is a wrong coolant causing electrolytical corrosion and eating away components. Any sediments usually end up getting dumped in the radiator, so this may be clogged. But since it is not a constant problem, the latter is unlikely.

Re: K series cooling problems

PostPosted: Tue Sep 09, 2014 10:15 am
by ACourtney
Hi Rich,

After seeing your car on Saturday, I can't help thinking that the problems you describe could be air locks. I've not seen such problems on a Midas, but then the K-series cars use the Rover plumbing exactly as it was originally designed.

I don't know how the pipes run front to rear on the K3, but I would suspect that they run along the floor. That would mean that the cooling system had two separate high spots that could trap air, one at the front and the second at the rear. You would therefore need to bleed both ends. It would also mean that the pipes could be a sediment trap which could cause intermittent blockages. It might pay to do a thorough flush through, refill and then bleed both ends.

It doesn't sound like a head gasket problem as usually once you have unsettled the gasket you will just overheat repeatedly. The randomness also reminds me of a problem I once had on my MG Midget that was cured by replacing the thermostat, so it could just be a dodgy thermostat.

Re: K series cooling problems

PostPosted: Tue Sep 09, 2014 10:56 am
by Rich
Thanks both, the pipes are the lowest point of the car which makes crossing speed bumps an interesting experience.

I'm going to take the front clamshell off, drain it and flush the radiator with the back end up on ramps. At the same time I'll probably turn the thermostat into a blanking plate in readiness for fitting a remote thermostat, I'd much rather it was running cool than hot for now.

Re: K series cooling problems

PostPosted: Tue Sep 09, 2014 1:09 pm
by wolfie
flush the system completely, check for any weeping around the water pump, make sure the cap on the expansion tank is sealing and finally do the old fashioned trick of dropping the thermostat in a jug of boiling water and time how long it takes to pop. In the past I've seen a lot of corrosion from the wrong type of coolant or only water with no coolant

Re: K series cooling problems

PostPosted: Sat Sep 13, 2014 2:33 pm
by Rich
Ok, done all that and now taken the head off.

Some of the liners have sunk slightly, there are fire ring marks on the head. The received wisdom would appear to suggest the engine is lunched. Arse.

Anyone got a sound 1.4 K series going begging?

Re: K series cooling problems

PostPosted: Sat Sep 13, 2014 5:36 pm
by Alan D.
Rich wrote:Ok, done all that and now taken the head off.

Some of the liners have sunk slightly, there are fire ring marks on the head. The received wisdom would appear to suggest the engine is lunched. Arse.

Anyone got a sound 1.4 K series going begging?


No,
But I have a 1.6K in stock.

Alan

Re: K series cooling problems

PostPosted: Sat Sep 13, 2014 6:07 pm
by Rich
Alan D. wrote:
Rich wrote:Ok, done all that and now taken the head off.

Some of the liners have sunk slightly, there are fire ring marks on the head. The received wisdom would appear to suggest the engine is lunched. Arse.

Anyone got a sound 1.4 K series going begging?


No,
But I have a 1.6K in stock.

Alan


Hi Alan,

It's ok, I've got a low mileage 1.4 on the way now. As I've already bought a pump, belt kit, gasket kit, PRRT setup and so on I'll fit them before fitting the new engine.