Running hot, new radiator, waterpump, thermostat and engine

Engines, Transmissions & Final Drive questions and answers

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emily_mx5
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Re: Running hot, new radiator, waterpump, thermostat and eng

Postby emily_mx5 » Wed Jan 01, 2014 10:43 am

If yours is an NA6,
I would trip the thermo fan to always be on, just take the wire that plugs into the top of the thermostat and crimp an eyelet to it, and ground that to any bolt in the engine bay.
No harm in having it always running.

Did you check the thermostat opens using boiling water?

Do you have the correct thermostat?
Ie maybe it is opening too late.

Put the under tray on, it's really important for airflow.

Head gasket wise, check the coolant for oil residue/scum floating in the radiator cap.
Check the oil for coolant residue/ milky coloured.


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sailaholic
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Re: Running hot, new radiator, waterpump, thermostat and eng

Postby sailaholic » Wed Jan 01, 2014 10:50 am

It might not hurt much for the fans to be always on but just band aids the problem.

Fans are also getting on in age, so it's likely to cause fan failure much quicker.


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Mr Morlock
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Re: Running hot, new radiator, waterpump, thermostat and eng

Postby Mr Morlock » Wed Jan 01, 2014 1:13 pm

I would advise on the side of caution. Having spent money on a replacement engine and other parts the seller and any contractor does owe you something. Surely the engine has some sort of warranty. An engine running hot is very dangerous- just running around the block can cause damage- modern engines are fragile when it comes to overheating. I would look into the engine warranty or however has done work on the car and ask them to rectify and or check. Our advice comes free but it also has no guarantee or comeback. Unless you are a trained mechanic or really over the issues consult someone who takes a responsibility.

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Re: Running hot, new radiator, waterpump, thermostat and eng

Postby Doug Danger » Fri Jan 03, 2014 3:35 pm

Undertray on, temp sensors all replaced. Freeway driving it moves to hot!

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Re: Running hot, new radiator, waterpump, thermostat and eng

Postby Doug Danger » Fri Jan 03, 2014 3:36 pm

The car went back under warranty and I watched them replace the parts. It's looking like its electrical but who knows?!

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Re: Running hot, new radiator, waterpump, thermostat and eng

Postby Okibi » Fri Jan 03, 2014 3:56 pm

If it gets hot at freeway speeds its got nothing to do with your fans.

Radiator could be blocked, thermostat could be buggered or the engine is cactus.

Have you had a compression check / lead down test done?
If you had access to a car like this, would you take it back right away? Neither would I.

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Re: Running hot, new radiator, waterpump, thermostat and eng

Postby OurCognitiveSurplus » Fri Jan 03, 2014 4:05 pm

Can you test to see if you have flow while warm?
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Mr Morlock
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Re: Running hot, new radiator, waterpump, thermostat and eng

Postby Mr Morlock » Fri Jan 03, 2014 7:03 pm

I reckon its not for you to check - if you change things they may blame you. If it cannot be resolved with the engine / fitter supplier you might need to seek some advice from a small claims tribunal- perhaps getting ahead of myself - the fitter may seek to send it to another specialist to resolve the issue. Talk to the fitter and ask them what they propose to do- and keep a record of what is said and when.

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Re: Running hot, new radiator, waterpump, thermostat and eng

Postby trader » Fri Jan 03, 2014 11:05 pm

My tuppence worth I reckon you have an air blockage in the coolant system. Try idling it on a steep slope (both ways) until it gets warm. After it cools down check radiator level and refill if down.
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Re: Running hot, new radiator, waterpump, thermostat and eng

Postby sailaholic » Fri Jan 03, 2014 11:58 pm

Checked base ignition advance?


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Doug Danger
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Re: Running hot, new radiator, waterpump, thermostat and eng

Postby Doug Danger » Sat Jan 04, 2014 7:26 pm

Again flushed system 3 times. Coolant temp still rising. Haven't checked base ignition advance. Would someone car to elaborate on that?

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Re: Running hot, new radiator, waterpump, thermostat and eng

Postby Doug Danger » Sat Jan 04, 2014 7:27 pm

Have to wait till Wednesday until I take it back. Would rather see if I can sort it before then :/

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Re: Running hot, new radiator, waterpump, thermostat and eng

Postby Doug Danger » Sat Jan 04, 2014 9:14 pm

The car has had the timing advanced to 14 deg BTDC

emily_mx5
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Re: Running hot, new radiator, waterpump, thermostat and eng

Postby emily_mx5 » Sat Jan 04, 2014 9:16 pm

Doug Danger wrote:Again flushed system 3 times. Coolant temp still rising. Haven't checked base ignition advance. Would someone car to elaborate on that?

yeah but did you bleed the air out of the system?

need a timing light for accurate ignition timing, but have a look at the cas, is it pointing straight up or tilted to either side?
try to match by eye from other NA8 engine bay pics.

take the timing back to standard lol.

check the static timing (timingbelt/cams etc). line up the cam gears to match the timing backing plate and check if the crank is on the 10 deg mark.

However my timing was way out once and it didnt affect temp at all.

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Re: Running hot, new radiator, waterpump, thermostat and eng

Postby Doug Danger » Sat Jan 04, 2014 10:48 pm

Will check static timing tomorrow now that I know how. As far as I'm aware there's no bleed valve for the mx5. I just used the method of jacking the car up and running until no more air bubbles are present and occasionally squeezing the top radiator hos. Cas looks to be in the right place (didn't go na8, went long nose b6).


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