68 replies to this topic

[S pack]

Water boils at 212deg F at atmospheric pressure at sea level. If you are running a 15PSI radiator cap the water temp will have to reach 257deg F for the water to boil.

30 something years ago I was experiencing all the same engine cooling temp issues as you are now. I installed a single 12"? Davis Craig thermo fan in front of the radiator and a KC Laser 95deg C thermo switch into the side of the thermostat housing coupled with a KC Laser thermo fan power relay. In conjunction with the LJ XU1 engine fan blade it keeps the temps under control.

[MFM]

I had the exact same issue with my XU1 which is how it came from factory other than a stamped impeller replacement waterpump (as can't but the cast ones anywhere). If I hit 2-3 sets of traffic lights in close proximity it would show 3/4 on the gauge BUT I didn't feel it was hot. A car behaves differently when hot and gets a smell to it, and the new 15PSI cap didn't spit anything out. I bought a new 170 thermostat but when I opened the housing, the one it it was 160? so I put the 170 in thinking the 160 was at least 20 years old (may be faulty) but made car worse so put the 160 back in but was advised to drill a hole in it. I bought the Red Devil Glycol and didn't dilute it, put it straight in and the bloody thing was worse again  . Turns out you have to mix that Glycol according to their recommendation/s  , so drained out a couple of litres and replaced with distilled water and bingo it now consistently sits just under 180 but still creeps up to about 190 on hot days idling but even at 190 you can place your hand on the top tank and its not boiling hot if that makes sense? So the lesson I learned from all this stuffing around it that the Glycol mixture ratios DOES  make a noticeable difference to the overall temperature, so perhaps play around with that.

[I'm a Red Motor fiend]

Seriously put a thermo fan in.
Air flow is your issue as mentioned earlier.
This couldn't be any more clear cut.

[ljv8]

Look I wish I knew what the problem is...I too am not running the heater. An update since last time I commented....
I had the tanks cut off and core checked and cleaned. Rad guy said about 10% had some crud in it but everything else was clean as a whistle. I pulled the 77 degree thermostat out and put a high flow 77 back in. Don’t want to go any lower as when moving it’s sits @77 no problems. It’s has definitely gotten better at the lights but it still won’t stop climbing. The thermostat has got a small hole in it from factory very similar to your ljv8. It takes about 5 minutes on an average day temp to go from 180f to 220f at idle in traffic. But if you get consecutive lights your in trouble! Question for you all....at 220f on the gauge it’s not showing any signs at over heating......no burping from the rad cap. Should it be at that temp? I’m starting to wonder if the temp sender being so close to the exhaust port is starting to throw off the actual water temp reading. I’m thinking about tapping a temp sender in the side of the lower thermostat housing where the heater hose feed is to try and get a true reading? Should I hook the heater back up to help with the cooling? Should I delete the water hoses from the inlet manifold?

My temp sender is on the head also, probably unlikely moving it will change anything.  Sounds like your out of options and might need to go the thermo route as suggested.   

[RallyRed]

Agree with the air flow idea.
Out of curiosity, is your temp.gauge original electric, or mechanical/ bulb type?

[evl666]

Original electric gauge. It corresponds to what the thermostat is and I also have a spare temp sender and boiled that up in a kettle while attached temporarily to the dash gauge and got the same reading. I know that it seems like air flow is the problem but in my eyes there should be a problem at all. That’s why I’m still hunting the issue.

[RallyRed]

Ok, yeah, air.
I only ask as I have just been playing around with stuff in this area.
Put a mechanical gauge sender into the head where the factory electric one normally lives.
No good.
Gets too much stray heat from exhaust...even with a heatsheild fitted.
i.e. reported the engine as red hot, it wasn't.
Ended up drilling both elec and mech gauges into thermo housing.
Elec = idiot light, mech = gauge.
FYI only, as it's a track car, so not relevant to road car.
I'd just try the thermo fan as suggested, or overdriven factory fan on your car.
p.s is it possible to fit the factory fan on backwards? I dont know.
Have you inspected the water pump itself?

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[evl666]

Pump is brand new with cast impeller. I’ll move the temp sender next and report back

[warrenm]

I had a similar problem with a fuel injected 12 port 202, I had the ecu coolant sensor fitted next to an exhaust port. While adjusting the tune, I noticed that the coolant temp was rising(230°+),because the tune was lean at idle, the temp gauge in the dash was showing 180°f, so I relocated the ecu sensor into the lower thermostat housing & both temps now read the same. So if your tune is a bit lean at idle, it could be lifting the temp. 

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[evl666]

Here is an update....checked the temp at the housing and the temp sender is telling the truth. It’s over heating. So I’ve deleted the manifold heating part of the cooling system and connected up the heater core. Now this has helped again, making it last longer at idle before it creeps up but it still eventually overheats. Anyhow I needed to change the oil pump as pressure was not really keeping up with the revs and I had a spare hv oil pump laying around so I through that on. Well that has made a difference as well. Still creeps up standing still but takes ages. More oil running around means more cooking I suppose. So I’m going to live with it like this and if all else fails I’m going to have no choice but to put a thermo on it. I’ve exhausted all I can think that’s going to help the issue without putting a thermo fan on.

[evl666]

*More oil means more COOLING....not cooking!

[warrenm]

The oil does the majority of the cooling of an engine. 

[S pack]

*More oil means more COOLING....not cooking!

10 out of 10 Fish & Chip shop owners would disagree.
 

[evl666]

So I’ve got 7 min at idle from going from 180f to 220f. I’m going to take it out around town and see how it goes light to light. I’ll take you guys advice on thermos now as I really have no choice. I was thinking 1 14inch in the front to do the job at idle.

[evl666]

Also it’s been suggested to me I should try a hq fan as that’s better that a lc one??

[claysummers]

Also it’s been suggested to me I should try a hq fan as that’s better that a lc one??

Read back in this thread, you want an LH LX fan. Whether HQ are the same, most likely.


Sent from my iPad using Tapatalk

[evl666]

This fan lx lh hq?

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[S pack]

LH/LX not the same as HQ 6cyl.

Edited by S pack, 25 February 2021 - 01:16 PM.

[evl666]

Can show me the difference so I know what I’m looking for?