VP cooling issues - checklist

[Morton]

Okie-day, I've pretty much always had cooling issues with the VP. She's no issue in winter, but come summer and spring, she likes to warm up. All it takes is a 20 degree day, and one set of red lights - 50% and rising. Not altogether normal. In summer, she races toward 3/4.

Now, I've taken preventative measures to make this summer easier - an override for my thermo fan. I can switch it on as soon as traffic builds up, to prevent the temperature getting out of hand. But I'd like to get this sorted

So here's the checklist:

1) thermostat (brand new, 82 degrees)
2) coolant (brand new, system flushed twice in 6mths)
3) water pump (brand new)
4) radiator (possibly factory, but still flows well when being flushed.)
5) blockage elsewhere

I'm thinking the issue rests with 4 or 5. BUT, I'm just posting first to ensure there's nothing so obvious that I've missed, which I could look at before spending big dosh on a new radiator.

EDIT: is it possible for the coolant temp sender to give a false reading to my dashboard gauge? (problem was relevant on old dash aswell as new)

[immortality]

the ecu and dash temp gauge have different senders so what oyu see on the dash could be different to what the ecu sees. try replacing the dash temp sender (single wire) and see what it does. if foam is doing you a tune maybe get him to drop the fan on and off temps to suit you new (cooler ) 82 degree thermostat also

[burnz]

two thing come to mind
1/sludge when you flushed the radiator did you flush the block?
2/the water pump is it a good brand? some lesser brands tend to airate the coolant

[timmy_tam]

can u share some info on how to make that override switch?

also, i don't imagine $100-$150 for a new radiator being too expensive, seeing as its the main cooling device in the whole car

[immortality]

can u share some info on how to make that override switch?

also, i don't imagine $100-$150 for a new radiator being too expensive, seeing as its the main cooling device in the whole car

check this thread, everything you need to know, ifoyu have any questions you can post it in that thread, a few people have done this mod, work well
How to fit thermo fan bypass switch

[Pub247]

LOL imortality your linky didn't work. I've this mod and it works very well i used stocky's idea of the power economy switch from the vr/s for my button looks neat.

[immortality]

LOL imortality your linky didn't work. I've this mod and it works very well i used stocky's idea of the power economy switch from the vr/s for my button looks neat.

should work now

[jas98]

heyi had an issu where my tep would rise to around half and up and my fan cut in aroung 3 quarters of the way............then one fay me fan did not come on.......so put air con on and temp went down....ended up changeing the coolent temperature sensor for the ecu and now the car runs heaps cooler (for some reason) and the fan kicks in lower then it did....................now i knoew this has nothing to do with the sensor for the guage but it did have an effect on mine for some reason

[Whitey]

heyi had an issu where my tep would rise to around half and up and my fan cut in aroung 3 quarters of the way............then one fay me fan did not come on.......so put air con on and temp went down....ended up changeing the coolent temperature sensor for the ecu and now the car runs heaps cooler (for some reason) and the fan kicks in lower then it did....................now i knoew this has nothing to do with the sensor for the guage but it did have an effect on mine for some reason

Old water temp sensors can send a false reading to the ECU - hence the computer thinks your car is colder than it really is and the thermo fan kicks in too late.

[RockyVX]

the sensor is only about $12.

check the coolant quality. several of the clean team and similar kmart/woolies brands work worse than plain tap water, by at least 5-10 degrees. and the scale on the temp gauge isnt too accurate. this could be part of your problem?

also using plain water, or tap water ****s up things with the minerals in it. use proper coolant, or a mix-your-own with demineralised water if you are not lazy!

you could also install a thero fan switch that activates from the radiator temperature. i think jaycar used to sell a thermo switch suitable for this when run through a relay.

[frustrated]

In the recent thread "Advice HELP please : Radiator got crack how much for new one ?", a few weeks ago, I posted a picture of the radiator I removed from my VP. About 1/3rd of the core was gummed-up with debris. Check the photo.

I too had had overheating problems, and the radiator seemed to flush OK.

I think your best bet is to actually take the radiator out of the car (very easy, half an hour's work) and give it a vigorous flush while holding it at various angles, particularly upside-down. Alternatively, or in addition to this, try to get a flexible tube into the top inlet pipe and ram it down as far as you can to try to loosen the gunge while flushing from the bottom pipe.

[Morton]

Well I've purchased a new coolant temp sensor and water temp sender. Hopefully I'll get a fine day to install them sometime soon

[timmy_tam]

morton, how much and where? i need some too but short of wreckers, where can i get some?
thanks!

[Morton]

Still have the receipt on the desk in front of me

TTS062: Tridon Water Temperature Switch: $12.35
TCS040: Tridon Coolant Temperature Sensor: $17.60

Total: $29.95

That was from Bursons. But if you can't find a Burson, try Repco, Supercheap or Autobarn in that order. They'll possibly be more expensive, but prices vary from place to place.

They're not the sort of thing you want to get second hand - just like an oil pressure switch or oxy sensor. Crap like that you're always best off buying brand new

[RockyVX]

frustrated - If you have played a fair bit, you would have a fair idea of what is going on as reguards flushing it, in other words, do it every time, and you will notice the difference if it is rooted. Also checking the cooling fins are not rusted out is also a good idea.

I did a head job (yeah. haha) on a Mitsubishi Express (Yeah. I know) company van a few years ago. and then explained to them that the head had cracked etc., as a result of the radiator being rooted, and the crapbox overheating. I then showed them that at least 2/3 of the radiator cooling fins were missing (rusted away), and explained that the radiator would only cool at around 1/3 capacity. thus they would be back next week for another head, and that I would not be responsible if they didnt get it fixed.

Sure enough, stingy little buggers said no, and had the old rad dumped back in. after picked up, it went really well for around 2 hours. then they hit the highway, did 120, and blew the ****er again. and tried to blame me for it.

morale of the story - check the radiator all over, not just flush it.

[frustrated]

RockyVX - I did flush the radiator properly on a regular basis, and used Holden coolant. I can't tell the difference between a completely new radiator and one with 1/3 of its core blocked, at least not with a simple garden hose test. Also, there was no external evidence of problems with the radiator - the fins were rusted on the outside. However, as you can see from the photo there was a pile of junk on the inside blocking the lower half of the radiator. The stuff looks a bit like the tablets you are supposed to put in after a flush; I've used this multiple times over the years.

[matty88]

Definately add a thermo switch, easy as pie to install, if you are sitting in traffic, whack the fan's on and she'll run cool all day