Troubles with my VK

[Dazza_Bo]

Hey everyone, new face here, you guys definitely seem to know your stuff and seem really helpful. I've browsed the forum for a while and have finally decided to join up.


I've had an old VK sitting around for a couple years and have recently decided to try and get it going again to hopefully get RWC and registered, but it's got a lot of problems.

Probably the most concerning is a rapid loss of coolant with no visible leaks. I'm worried it might be a blown head gasket, and from what I gather it is pretty expensive to get fixed? Anyone have a rough estimate? Another thing I've noticed is my temp gauge doesn't seem to work. Just stays completely to the left. Do you think these two things are related?

I'm pretty hopeless when it comes to cars but I'm trying to learn, mostly from here and my Gregory's service manual.

Cheers.

[ari666]

they could be related, but clearly fixing the temp guage will give you a much better idea of whats going on in the engine, i.e. whether or not its overheating.

the loss of coolant might be something as simple as a blocked radiator, thus overheating and spitting all your coolant out of the overflow. so yeah, agenda point 1: get the temp guage working.

[Dazza_Bo]

Thanks for the advice mate. Sorry to ask another stupid question but how would I go about fixing the temp guage? Or could you point me in the right direction on the web that explains how to fix it? Like I said I'm pretty hopeless when it comes to cars.

Cheers.

[ari666]

well, nine times out of ten itll be the sender. its a switch on your water gallery which has a range of resistance depending on how hot it is. you can test it with a multimeter, or a more basic test is to earth out the wire thats connected to it. i.e. get someone to watch the guage as you hold it on something earthed.

im pretty sure that these are open circuit till they get hot which is closed circuit, so earthing it should make the temp guage go off the charts. then if the guage works ok, you need to replace the sender.

edit* these are not stupid questions btw. stupid questions are "what do i have to change to fit a V8 to my 6cylinder VK" which has been answered 100 times already. yours are questions i enjoy

[Dazza_Bo]

Alright cool. I'll give that a shot probably tomorrow arv, and I'll let you know how it goes. Thanks again.

[Dazza_Bo]

Sorry for the double post but could someone link me to a pic of the sender, so I know I'm testing the right wire?

[ari666]

i havnt got a pic cos i dont have a 6, but this is what it roughly looks like:


on a holden V8 its right at the front on the inlet manifold. no idea where it is on a 6 though, sorry.

[VK SL 3800]

Back of cylinder head left hand side when you stand looking at engine. just under tappet cover gasket so its almost always covered in grease. looks same as the other pic but with a horizontal round connector for the wire. Blown head gasket will normally have a range of other problems as well, poor idle, white smoke, low compression. Sometimes they will pressurise the cooling system.

[Dazza_Bo]

Thanks for the pics and info, it was easy to find with all the help. Earthed the wire and the needle almost jumped off the dial so it looks as though ari666 was spot on. Cheers dude. I'll go down and grab a new one tomorrow when I get paid and slap it in, see what happens from there I guess.

[ari666]

cool once you have changed that it wont fix your problem, but will make it loads easier to diagnose so make sure you post up and let us know what happens

im still betting on a blockage in the rad and spitting water out the overflow, but we shall see.

[codfishface]

Make sure your engine is stone cold before removing the old sensor.

Hot water, pressure and bare skin do not a good mix make.

[mainpath]

You might need an adaptor as the new temp sender is slightly different to that was originally in the car.
Repco have them.
I needed on for my VB.

[VK SL 3800]

Vb still run a red motor and the sender is different to vk, vk sender is the same as a commodore V6 one.

[Dazza_Bo]

So I put the new one in just before and connected the wire back on top, started the engine and nothing. The needle is still staying to the left. Could it be a bad connector from the wire to the terminal of the sensor? I earthed the wire again and the needle still climbed like crazy so I'm lost.

[ari666]

did you warm up the enigne? i.e. take it for a fang? is there water in it?

[Dazza_Bo]

I let it idle for a couple minutes. Should I take it for a run around the block instead? I don't like driving it much because it's unregistered.

Edit: Disregard that. I suppose I should have taken it for a spin before deciding the new one was buggered too. Works fine. So do you think a radiator flush should be the next agenda? See if that sorts out the coolant dissapearing?

[ari666]

hmmm, i didnt realise it was dissappearing while not being driven... now i would be looking more for a leak in the system, and i would suggest looking at the heater core first. does the carpet get wet on the passenger side floor?

[Dazza_Bo]

Sorry I didn't mean that it was dissappearing while not being driven. I drive it about 15 minutes up the road to my workmates house before work and 15 minutes back home in the afternoon everyday (naughty I know), which is when I'm losing the coolant. I just meant that I don't like to drive it if I don't absolutely have to.

[ari666]

well lets see what the temp guage says over the next few day of course you are driving it with a 30 day reg and your "mates place" is actually a place of repair, thus making it allll legal

[Dazza_Bo]

Oh of course.

[Tree cutter]

After you have taken it for a run and turned the engine off. open the bonnet and feel around the bottom of the water pump to see if any coolant is leaking out there. There is a drain hole on the bottom of the water pump that lets coolant drain out if the seal on the pump shaft is worn.

[ari666]

ah yes, very good suggestion. its easy to miss that seal too.

[VK SL 3800]

And watch for excessive whit smoke on cold start up, bit hard to tell in the cold weather though.

[Dazza_Bo]

Well, work was cancelled this mornin because of all the rain around so I got a chance to drive the car around a little more to see what the temp guage said. Seemed fine, only got a little bit past the second bar, the one after the first blue bit. After I got it home, I thought I'd have a look under the water pump to check what Tree cutter suggested. I undid the screws on the fan shroud to move it forward to make it easier and as I looked down guess what I see. A big ass pool of coolant in the bottom left hand (as you're looking at the car, drivers side) of the radiaotr mount (not sure if this is what its called, the bit that the radiator sits on). It was underneath where the lower radiator hose connects to the radiator so I checked all around the hose and connection to try and find a leak but couldnt find anything?

What could it be? Crack in the radiator itself? I'll try and take some pics later today so I can give you guys a better description because I'm probably not explaining it very good. Also how the hell do I get the shroud out of there? Do I have to take the fan off first?

Edit: Took some pics.





Cracked radiator?

[Dazza_Bo]

From what I can see there seems to be a crack in the side of the radiator and once the cooling system becomes pressurised it starts leaking quite a bit. A mate of mine know a few people who may have a VK radiator laying around, so he's asking for me. One of them was saying something about a V8 radiator, but I dunno. I thought it would be too big?