VE SS Getting Hot

I have a 2006 VESS A6 with a 406 stroker and makes 540rwhp.

Recently, I was replacing the water pump and decided to go electric. Since then, and in no way connected to the water pump replacement, I had to replace the radiator thermo fans and motors and the radiator.

Last week, I was towing my ski boat and on the open road it was fine, water temp sitting around 95 degrees. However, when going through towns, she started heating up to over 100. And when I was backing it into the shed at home, it hit 118.

Prior to the water pump change, it has never gone over 100 degrees no matter what I was doing.

Do you think the electric water pump is letting me down or could it be something else.

EWP's aren't that great at being the only pump in a system, they can work well as a booster but I'd never use one standalone.

Having said that the 95/100 range sounds about right if you have a factory thermostat in it, my 402 runs around those temps with all the additional coolers in front of the radiator.

118c is time to panic though....

Hi there,

My brother had a similar problem with his HSV. He ended up putting multiple fans behind the radiator and it normalised the temperature. He actually changed the plastic ones for metal fans and they were bigger in size. I couldn't give you the exact sizes but I can find out if that would be of any assistance.

Cheers Mark

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Originally Posted by IJ.

EWP's aren't that great at being the only pump in a system, they can work well as a booster but I'd never use one standalone.

Having said that the 95/100 range sounds about right if you have a factory thermostat in it, my 402 runs around those temps with all the additional coolers in front of the radiator.

118c is time to panic though....

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Not sure about the thermostat. Would changing it improve (lower) the operating temps?

Don't worry, I was panicking when she hit 118. Lucky I was just reversing the boat into the shed.

Mmmm - so should I go back to the mechanical pump?

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Originally Posted by HOLDAN

Not sure about the thermostat. Would changing it improve (lower) the operating temps?

Don't worry, I was panicking when she hit 118. Lucky I was just reversing the boat into the shed.

Mmmm - so should I go back to the mechanical pump?

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I would and then if you have room run something like a DC EWP as a Booster to fill in any holes, The T Stat change just seems to delay any issues, as I said mine seems to find an equilibrium of 95ish cruise and 100 in traffic, I tried a lower T Stat and all it did was take longer to hit it's happy place.

If you had a lot of overhead in the cooling system a lower T Stat would allow it to run cooler but in my VZ that just isn't the case.

Being a bit old school I totally freaked out the first time I drove this thing in traffic and it went above 100c ;)

Yet more evidence electric water pumps are not that great

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Originally Posted by macca_779

Yet more evidence electric water pumps are not that great

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Only ever used them as Boosters Macca, just to cover the lack of flow at idle and cavitation at high rpm, I think the MBTF is very low, far too short a life to rely on one for daily use, be interesting to see how much more current Dan's is pulling now it's slowing down..

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Originally Posted by IJ.

I would and then if you have room run something like a DC EWP as a Booster to fill in any holes, The T Stat change just seems to delay any issues, as I said mine seems to find an equilibrium of 95ish cruise and 100 in traffic, I tried a lower T Stat and all it did was take longer to hit it's happy place.

If you had a lot of overhead in the cooling system a lower T Stat would allow it to run cooler but in my VZ that just isn't the case.

Being a bit old school I totally freaked out the first time I drove this thing in traffic and it went above 100c ;)

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Pardon my ignorance but what is "overhead in the cooling system"?

Would an OEM replacement water pump suffice, or should I get something with more flow etc?

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Originally Posted by HOLDAN

Pardon my ignorance but what is "overhead in the cooling system"?

Would an OEM replacement water pump suffice, or should I get something with more flow etc?

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"Overhead" as in a HUGE high efficiency radiator that can easily cope with the heat your engine is producing, i.e. running a 6 cyl engine with a V8 cooling system in the old days ;)

Don't really know of anyone making a "better" mechanical pump but have read lots of horror stories about non genuine ones..

<edit> Quick search shows Edelbrock make one they claim is 12% better flow at low rpm..

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Originally Posted by IJ.

"Overhead" as in a HUGE high efficiency radiator that can easily cope with the heat your engine is producing, i.e. running a 6 cyl engine with a V8 cooling system in the old days ;)

Don't really know of anyone making a "better" mechanical pump but have read lots of horror stories about non genuine ones..

<edit> Quick search shows Edelbrock make one they claim is 12% better flow at low rpm..

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OK that makes sense. I just put a new radiator in it. Asked if I needed a bigger one and the consensus was no. I never had any problems at all until the change to electric. We put another camshaft in at the same time and made another 70rwhp. Not sure if that's what pushed it beyond the oem limits.
Stewart make one too:
http://www.stewartcomponents.net/Mer...y_Code=ChevyS4

Not seeing an LS one's on Stewarts page??

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Originally Posted by IJ.

Not seeing an LS one's on Stewarts page??

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Oh OK - I din't look that closely. :(

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Originally Posted by HOLDAN

Oh OK - I din't look that closely. :(

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LOL so you can have an Edelbrock one or an.. Edelbrock one ;)

Getting a little pricey once you add in a Pulley for it, VPW stock them.

If anyone else knows of alternatives please jump in as it's something I'd like to address as well.

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Originally Posted by IJ.

LOL so you can have an Edelbrock one or an.. Edelbrock one ;)

Getting a little pricey once you add in a Pulley for it, VPW stock them.

If anyone else knows of alternatives please jump in as it's something I'd like to address as well.

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Yes indeed - Edelbrock it is.

I was talking with my mechanic last night. He said my issue sounds like a thermofan issue. I had a fan replaced recently by Holden - it could be spinning the opposite direction. I will check that when I get home next Monday.

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Originally Posted by HOLDAN

Yes indeed - Edelbrock it is.

I was talking with my mechanic last night. He said my issue sounds like a thermofan issue. I had a fan replaced recently by Holden - it could be spinning the opposite direction. I will check that when I get home next Monday.

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I'd imagine a Holden supplied Fan would have the correct connector on it and just plug in... if not it's an easy fix :)

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Originally Posted by IJ.

I'd imagine a Holden supplied Fan would have the correct connector on it and just plug in... if not it's an easy fix :)

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Yes I agree. Hopefully though they have wired it the wrong way and that will solve my problem

Have you tried a different coolant? ie non water based/waterless type coolant .

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Originally Posted by XUV

Have you tried a different coolant? ie non water based/waterless type coolant .

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From my research they typically run hotter....

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Originally Posted by IJ.

From my research they typically run hotter....

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Then what's the go/use of them ??

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Originally Posted by XUV

Then what's the go/use of them ??

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Reduced pressure in the system and they're pimped as lifetime coolant no need to ever change it...

I always dismiss the suggestion or use of a cooler thermostat cause @ the end of the day only cooling capacity you have is in your Rad! If your std thermostat is serviceable & the motor is hot the stat is gunna be fully open! Otherwise do away with it & will be a pig till it's warm.
Need more cooling capacity a greater capacity Rad is required larger tanks & more fins/inch etc!
In the three LS engines Ive had so far had no reason to touch/upgrade the stats or Rads they work really well & have noticed the 6L E38 controlled ones cycle fans even better than the previous ECU!!

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Originally Posted by Micks

I always dismiss the suggestion or use of a cooler thermostat cause @ the end of the day only cooling capacity you have is in your Rad! If your std thermostat is serviceable & the motor is hot the stat is gunna be fully open! Otherwise do away with it & will be a pig till it's warm.
Need more cooling capacity a greater capacity Rad is required larger tanks & more fins/inch etc!

In the three LS engines Ive had so far had no reason to touch/upgrade the stats or Rads they work really well & have noticed the 6L E38 controlled ones cycle fans even better than the previous ECU!!

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I agree. I have had absolutely no problems at all in the 7 years I've had the car. Towed my ski boat all over the country, taken it (car not boat) to the strip a few times - no dramas. Now, it runs at the right temp on the open road, and gets hot when the fans are in play. So I'm guessing there is still a fan issue.

I returned home this arvo. Tested the thermo fans and all is good with them. However, I noticed some coolant leaking from under the radiator cap.

Now I had the radiator relplaced by Holden a couple of weeks ago. After I got it back, I was checking the coolant level. I noticed the radiator cap was extremely hard to get off. and I'm no weakling. It was never that hard before. Thought it was because it was all new and tight. I also thought maybe it was cross threaded. Anyways, I have had the cap on and off a few times and it is still very tight. So I haven't been tightening it all the way down (thinking of the cross threading issue). However, with a shite load of grunting, I screwed it down so there was no leakage, Took it for a spin - seemed ok. Could a loose cap be causing my overheating issue? SHould the cap be that friggin hard to screw down?

Absolutely shouldn't be that hard. There will definitely be some resistance but anyone should be able to get the cap off with relative ease, even a kid. If the spring pressure on the relief (under the cap) is shot then you'll boil the water sooner and wont have the same heat transfer capabilities which could lead to overheating. The steam would go into the overflow tank so unless there's a fair amount you might not even notice it.

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Originally Posted by HOLDAN

I returned home this arvo. Tested the thermo fans and all is good with them. However, I noticed some coolant leaking from under the radiator cap.

Now I had the radiator relplaced by Holden a couple of weeks ago. After I got it back, I was checking the coolant level. I noticed the radiator cap was extremely hard to get off. and I'm no weakling. It was never that hard before. Thought it was because it was all new and tight. I also thought maybe it was cross threaded. Anyways, I have had the cap on and off a few times and it is still very tight. So I haven't been tightening it all the way down (thinking of the cross threading issue). However, with a shite load of grunting, I screwed it down so there was no leakage, Took it for a spin - seemed ok. Could a loose cap be causing my overheating issue? SHould the cap be that friggin hard to screw down?

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No a loose cap will lower the system pressure & lower the temp slightly! Depends how bad it's leaking.

Mmmmm - no I'm confused............

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Originally Posted by Micks

No a loose cap will lower the system pressure & lower the temp slightly! Depends how bad it's leaking.

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Are you sure mate ??? I would have thought a lower system pressure would = a lower boiling point & therefore make the engine prone to overheating.

That's right Pete, until the coolant boils off & depletes the system of capacity. The OP is talking about a slight leak at the Rad cap!
What I'll do both my 6L's have Rad caps will leave the cap half a turn proud & run it up till hot & record the temp.

Ran the car in the middle of the day today and in stop start traffic - temp ranged between 92 and 96. All good it seems.

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Originally Posted by Micks

That's right Pete, until the coolant boils off & depletes the system of capacity. The OP is talking about a slight leak at the Rad cap!
What I'll do both my 6L's have Rad caps will leave the cap half a turn proud & run it up till hot & record the temp.

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Ok ran my Z till warm & recorded 96.4 @ ambient of 25.5, cracked the cap @ idle took it for a 15min stop/start run & recorded 99.7 with a little coolant streaming out of the cap. So about 3 degrees increase with press relieved.

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Originally Posted by Micks

Ok ran my Z till warm & recorded 96.4 @ ambient of 25.5, cracked the cap @ idle took it for a 15min stop/start run & recorded 99.7 with a little coolant streaming out of the cap. So about 3 degrees increase with press relieved.

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OK Thanks for that. Mine hit 118 while backing my ski boat into the shed after towing the boat for an hour.

Today it ran 92 to 97 in the traffic.

Reckon you have it nailed!

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Originally Posted by Micks

Reckon you have it nailed!

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Yes I reckon I might. Taking the boat out on Saturday. We'll see what happens then before I call this busted.

So what was the fix Dan?

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Originally Posted by IJ.

So what was the fix Dan?

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Screwing down the radiator cap - took all my strength and then the aid of multigrips to get it screwed down all the way. I never had to use that much force before - even when the car was new. Holden told me it was because of the new o-ring in the cap....................

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Originally Posted by HOLDAN

Screwing down the radiator cap - took all my strength and then the aid of multigrips to get it screwed down all the way. I never had to use that much force before - even when the car was new. Holden told me it was because of the new o-ring in the cap....................

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Very interesting thanks Dan!

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Originally Posted by Micks

No a loose cap will lower the system pressure & lower the temp slightly! Depends how bad it's leaking.

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Originally Posted by Peter B - CV8

Are you sure mate ??? I would have thought a lower system pressure would = a lower boiling point & therefore make the engine prone to overheating.

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A lower pressure will result in a lower boiling point.
Raising the pressure will just raise the point at which the coolant boils, but will not change the cooling characteristics of the coolant, nor will it reduce the overheating tendency of the engine - just delays the inevitable.
But what it will do is prevent fluid being forced out and depleted, which reduces the cooling mass of fluid

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Originally Posted by seldo

A lower pressure will result in a lower boiling point.
Raising the pressure will just raise the point at which the coolant boils, but will not change the cooling characteristics of the coolant, nor will it reduce the overheating tendency of the engine - just delays the inevitable.
But what it will do is prevent fluid being forced out and depleted, which reduces the cooling mass of fluid

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yeah, you could look at it like if you pour water from a glass onto a hot plate it'll just boil n bubble away ,
but flip that glass of water over and force that water onto hot plate in the confines of the glass , you'll cool that spot.