Rusty's Project

[muley]

Perhaps I should change the thermostat. There was a suggestion in the bottom half of page 1 of this thread that this might not be closing properly. But, if this were the problem, I would expect the fans to switch on.

True.


Jim

[Enright]

For the cost of a thermostat and the peace of mind that having replaced it offers, I would almost say daft not to.
In the last few years they were available from Halfords for about £6-7, but I haven't looked recently.

I can't quite remember, but I think that if it's stuck shut then it prevents the hot water from reaching that red rad fan thermal switch in the pic on the previous page (which seems a bit silly, but I guess that's just one of those foibles we're going to have to live with now)!

[Brit-Car-Nut]

If you install it correctly, with the jiggle pin or bleed hole at the very top, the water will always reach the sensors.

Replacing it for the first time can be a task. The thermostat sits in a shallow recess and it loves to fall out as you start tightening the housing into place. That always causes a small leak. DON'T try to tighten it to fix it because the housing can crack. Clean up all of the surfaces and use a little gasket cement to hold it in place or hold it in place and glue the gasket over it to hold it as you install the housing.

Just for the knowlege, before you do anything else, make sure you don't have a small leak and the water level hasn't lowered as that will cause the symptoms you have noticed. Maybe a good flush while you do the thermostat should be considered?

[hodge]

For the cost of a thermostat and the peace of mind that having replaced it offers, I would almost say daft not to.
In the last few years they were available from Halfords for about £6-7, but I haven't looked recently.

I can't quite remember, but I think that if it's stuck shut then it prevents the hot water from reaching that red rad fan thermal switch in the pic on the previous page (which seems a bit silly, but I guess that's just one of those foibles we're going to have to live with now)!

Yes this is true, the sensor/thermal switch which completes circuit to the fans (red in the pic), is on the other side of the thermostat to the coolant temperature sensor (which informs ECM) and the sensor for the dashboard temperature gauge, which means if the thermostat is stuck, coolant can be hot on one side (engine side) of the stuck thermostat and cool (below fan switching temperature) on the other. In this case you'll see the temperature rise as will the ECM but the fans won't switch on, they would'nt do much good if they did tho, as in this scenario coolant is only circulating around the engine via the radiator bipass pipe and not reaching the radiator.
An eyebrow raising situation for sure.
Halfords used to do two thermostats, their own brand and a Quinton Hazel QTH100K but when I last went for one they'd stopped stocking them. This situation may change as their policy re product lines seems to be up and down of late. Andrew Page do the QTH100K and Eurocarparts list a Vernet (pt no 209770300 currently reduced from £11.28 to £7.80 ) as a compatible 82c thermostat, I haven't seen one of these but their photo shows it to have the small crimp to allow air bleed from the engine side, as per the lotus supplied part apparently. Guess who's just replaced his thermostat
edit - John posted as I was writing, the jiggle pin/bleed hole is same as the crimp I referred to, if placed at top it will allow coolant to rise high enough for the sensors in the thermostat housing to give a good reading. Doubt if it would allow enough coolant to pass to trigger the fan switch if the thermostat is stuck closed tho.

[Nickydee]

My car has always run cold. I replaced the thermostat with one with a part no from the wiki (the Mini 1000 one). Still run cold. Replaced it last weekend with a Lotus one which unlike the previous one has the stat off centre and a jiggle pin described above . The car is now running at the correct temp. For sake of few pounds( I think the Lotus stat was £14), I wouldn't now bother with a non lotus one.
I suggest the WIKi is updated not sure how to do that through.

[novacaine]

My fans work ok, they just come on when the temp gauge is just above half way. Is that a sign of the thermostat not working or could it be the CTS? The previous owner had a thermostat fitted not so long ago, but I have no idea if its a lotus one or some other.

[Rusty Wishbone]

Some more poking around this evening:

1. Slight whistle when driving the car which can be heard in the background to the normal noise of the engine.
2. Coolant is present and correct.
3. The electric fan doesn't come on, even as the temperature gauge approaches H.
4. Radiator top hose doesn't get hot.
5. Lots of gurgling as the car cools after the engine has been switched off (this might be normal).

I'll start by replacing the thermostat, failing which, perhaps it is the water pump? I'm very glad that I spotted the temperature gauge rise.

So, the Elan has now done 1100 miles before letting me down. Looking on the bright side, I call that a thousand miles of trouble-free motoring!

[Brit-Car-Nut]

It does sound like a bad thermostat. Use a Lotus one so you can be sure. Remember, the jiggle pin goes at the very top.

[Enright]

I'll start by replacing the thermostat, failing which, perhaps it is the water pump? I'm very glad that I spotted the temperature gauge rise.

So, the Elan has now done 1100 miles before letting me down. Looking on the bright side, I call that a thousand miles of trouble-free motoring!

Technically, it's still going and could even be relied upon for short hops, so it's not quite let you down yet (although I accept that it's on the verge of doing)!
But having to replace a thermostat on a 20-ish year old car isn't so bad - it could almost be considered a consumable, and at least it's one of the more accessible jobs.
Wow, how defensive of the marque am I getting?!?

Rusty, just one query which concerns me a bit about your post: you say the fans don't come on when it gets hot.
Due to the placement of the sensors being on the cold side of the potentially dodgy stat, I would obviously try and avoid letting it get hot any more - you WILL be putting strain on your head gasket as it's going to be getting a lot hotter than it's registering.

The other thing is, have you tried earthing the aforementioned thermal switch to trigger the fans and/or coolant pump? I've found you can do it against the corner of the oil separator, and try it both with the ignition on and off.

[Rusty Wishbone]

The Lotus thermostat is now on back order, so I've ordered SJ's equivalent.

[Enright]

Hope it didn't cost too much:
http://www.ebay.co.uk/sch/i.html?_odkw= ... K&_sacat=0

[Brit-Car-Nut]

I believe the stat I used also was off center and had a jiggle pin. The Mini Stat is centered so the water flow over the wax ball is not correct. The proper stat is reasonably easy to get in the US, so maybe someone should order a bunch to provide the correct stat when the local stores don't have any. I bought a Stant 45858: $5.12.

[Rusty Wishbone]

It does sound like a bad thermostat. Use a Lotus one so you can be sure. Remember, the jiggle pin goes at the very top.

Thank you for saying this. I whipped out the old thermostat this evening without noting its position. It was quite a nice job, actually, which can be completed in an evening even by a novice like me. I'll take her out tomorrow evening to make sure there are no water leaks.

I boiled up the new and old thermostats in a pan - the old one didn't open at all, so I'm confident that this problem has been solved. I was struck by the fact that the coolant looked pretty murky, so I had better get on and replace it, and that will give me a good excuse to install those Samco hoses.

And thank you to everyone who chipped in with helpful comments.

[Enright]

Rusty,
Quite a lot of coolant system issues in the past (including head-gasket failures) have been caused on Elans due to failure to change the coolant regularly.
It should be done annually, or at least every other year, otherwise it loses its effectiveness, ionises and corrosion is accelerated.
There's a good topic about it here: viewtopic.php?f=122&t=19956
If you undo the big hose that goes into the chargecooler from the turbo, you can just about reach down past it and get to the drain plug in the bottom corner of the radiator, although you may need another elbow!
After that, give it a good backflushing and use de-ionised water to dilute the anti-freeze when you top it back up (it's available from Morrisons for just 49p/litre, and you only need 2, and maybe a spare).
Don't forget to loosen the bleed screw in the passenger side headlamp pod recess when refilling, to get rid of the airlock.

[Rusty Wishbone]

All is well! The car now runs hotter than before - needle touches the underside of the 1/4 mark when up to temperature instead of the underside of the zero mark. So that should make it a little more fuel efficient.

[Rusty Wishbone]

The brake pedal feel on my car is awful, vibrating as the brakes are applies. I've decided that it is time to change the front discs. The current ones are grooved EBCs and don't look very worn, so I thought that I would try inexpensive Vauxhall Astra ones to see if that fixes it. Does anyone have a part number for these? I imagine that different Astra models had different discs.

[inkitin]

Does anyone have a part number for these?

I bought these 18 months ago and they're working fine for me.

[Rusty Wishbone]

I bought these 18 months ago and they're working fine for me.

Thank you. £26 for a pair of Brembo discs sounds good to me. I have ordered them. I'll let you know how I fare.

[inkitin]

Glad it helped.

Yes please, let us know how you get on with them.

[cliff]

Good that is sorted, good luck with the brakes.

Maybe the moderators would like to move this to the Projects forum.