warming up too quick

graeme · Post by **graeme** » Sat Jul 14, 2007 9:44 am

My car has started getting from cold to 87degrees quicker and quicker.

At first I thought the stack temp sender might be dud, but then the fan does seem to come on at the right numbers, and that's driven by the ECU sender, so the stack and ECU appear to think the same thing... they might both be dud, but it seems weird.

Anything I can look at? Maybe air in the system (don't know why... just guessing).

Other poorlyness at the moment which I'm investigating seperately is that the natural idle speed is getting lower and lower. I did a ignition-press accellerator a few times-ignition off and that made it lots worser. Don't think it's related to the temp issue, but I thought I'd throw it in just in case.

I'm loving the niggles! I'd forgotten how much there is to figure out with these little cars...

TIA for advice..

Post by **Shug** » Sat Jul 14, 2007 9:55 am

Does it get up to temp, then stay there? Or is it overheating too?

graeme · Post by **graeme** » Sat Jul 14, 2007 9:57 am

Nope, not overheating at all. Temp stays normal and fan cuts in at the right numbers as usual. Just gets from 0-87 deg far too quick!

Honestly don't know if it really is heating up that quick (no more heat being generated, so must be a cooling failure) or if the numbers are telling fibs.

Worth £30 to change brown and blue senders to see if it goes away?

Post by **Shug** » Sat Jul 14, 2007 10:11 am

Well, if it's reporting the right numbers when up to temp, it ain't gonna be the senders is it?

How quick is quick? I mean if the cooling system is still handling it, it can't be bad. Don't think it would be the thermostat, as a lazy 'stat would make slower to get to temp. Unless, it wasn't used regularly by the last owner and everyday use has slapped the stat back into life?

mac · Post by **mac** » Sat Jul 14, 2007 10:30 am

Check the underside of the radiator for ingested newspapers, leaves, small children and animals

Mac

graeme · Post by **graeme** » Sat Jul 14, 2007 10:54 am

No, I don't believe it's the senders as stated, but if the jedi's want to prove it's not them before devoting brain-power to my debugging, I'd understand...

My commute is about the nastiest journey you could do in a S160... Stop start traffic from the end of my road to the office.

I know that a couple of weeks ago it consistently took most of the way to work (15 ish mins) to get up to temp.

Now, it's taking about 1/3 of the way to work (5 ish mins) to reach top temp.

Not exactly a scientific measurement, granted, but it's definitely happening... ambient air temp is dropping if anything, traffic levels are fairly constant.

I did see something once last week which might help... the stack read 87 after a quick warm-up. I booted it away from a roundabout and the temp dropped to 75 instantly, then slowly crept up to 87 again. That was a one off, but made me think of a loose wire or an air pocket in the system. Any help?

I'm cr*p at stuff like this. Too many variables and not enough knowledge and experience of enjins!

mckeann · Post by **mckeann** » Sat Jul 14, 2007 11:15 am

5 mins is fine. the temp getting up to 87 then dropping to 75 when you boot it is also fine. Its because there is still cold water in the radiator, and also the higher the revs, the quicker the water pump spins.

nothing to worry about you big homo

graeme · Post by **graeme** » Sat Jul 14, 2007 11:19 am

mckeann wrote:Its because there is still cold water in the radiator, and also the higher the revs, the quicker the water pump spins.

Makes sense. Ta. Forget about that 87-75 drop then...

mckeann wrote: nothing to worry about you big homo

There's still a change. Why would it go from 15 mins to warm up to 5 mins, gradually over a couple of weeks? If it's nothing to worry about, fine, but it's worth askin'!

Post by **Shug** » Sat Jul 14, 2007 12:17 pm

graeme wrote:
mckeann wrote:Its because there is still cold water in the radiator, and also the higher the revs, the quicker the water pump spins.
Makes sense. Ta. Forget about that 87-75 drop then...

mckeann wrote: nothing to worry about you big homo

There's still a change. Why would it go from 15 mins to warm up to 5 mins, gradually over a couple of weeks? If it's nothing to worry about, fine, but it's worth askin'!

'Cos, like I said - it's possible the stat has freed up with regular use.

Stop bloody worrying - worry when there's a plume of steam.

graeme · Post by **graeme** » Sat Jul 14, 2007 12:25 pm

OK. Ta.

Rich H · Post by **Rich H** » Sat Jul 14, 2007 4:05 pm

Its a 160, its not if it's when...

Take it out for a bit of rough love and see what happens. If it gets to temp and stays put there abouts then stop worrying. If it doesn't....

Post by **campbell** » Sat Jul 14, 2007 11:52 pm

It's all just bl**dy global warming man. Stop flying, stop using electricity, stop driving, stop using your fridge, stop exhaling CO2 and we should all just about be OK.

sheesh.

Victor Meldrew · Post by **Victor Meldrew** » Sun Jul 15, 2007 12:06 am

campbell wrote:It's all just bl**dy global warming man. Stop flying, stop using electricity, stop driving, stop using your fridge, stop exhaling CO2 and we should all just about be OK.

sheesh.

Ahhhh heathen....

robin · Post by **robin** » Sun Jul 15, 2007 6:37 am

The stat is still closed almost the whole way during the warm up phase to 87C; the fact that it stops at 87C means the stat is opening.

Either shug is right and the stat was stuck open a bit, so you were having to warm the whole cooling system, water in rad included, before getting to 87, but then the temp would have been really low on the motorways (stat stuck open, motorway cruising, temp < 60 is easily possible).

The other factor that effects how well the cooling system works is how much anti-freeze there is in your coolant. Anti-freeze lowers the effectiveness of the coolant (which means the coolant heats faster).

S160's not idling appears to be a common fault, most likely related to the TPS or IACV. I would also check your air intake for small mammals, etc.

Cheers,
Robin

graeme · Post by **graeme** » Sun Jul 15, 2007 9:18 am

Robin, you've hit the nail on the head. It had a coolant top-up about 2 weeks ago, and I can tell they didn't use the oem stuff as tis the wrong colour. This coolant gets hot quicker = buckets of antifreeze in it...

Didn't mention that as I had no idea that different coolants behave differently...

Cheers,
Graeme