VF SV6 Coolant Leak?

[VryBigPP]

Hey all,

Last week I had my radiator replaced in what seemed to be a failure of it, which caused a coolant leak and engine overheating. Symptoms then included rapidly fluctuating engine temperatures, a slight leak coming from just behind the oil closer towards the transmission, and what sounded like a boiling/bubbling sound from the coolant reservoir, and what it looked like was that coolant had boiled over the cap as there was moisture all the way up the stick, but no red coolant showing at all.

Fast forward to now, after getting home from a drive I hear what sounds like boiling/bubbling from the coolant reservoir again. I check underneath the car and it's experiencing a slight leak again in the same spot (which had stopped happening when the radiator was replaced). After letting it cool down overnight, I checked the coolant reservoir dipstick and it's sitting on the "minimum" line, which after looking at other threads appears to be expected if it's cold. I haven't experienced any notable temperature fluctuations or anything past what could be considered normal operation, I'm just concerned with another apparent leak that this will quickly become an issue again, and whether it's the radiator or not I've got no clue, but I'd much rather be safe than sorry and catch this out ASAP. After letting the car run for a bit the coolant reaches a bit higher on the dipstick, but nonetheless I'm still concerned about any leak.

I'm unable to see any mechanic until tomorrow at the earliest, so any advice would be much appreciated.

 

[gossie]

Park it and see mechanic tomorrow as you say.
Does he/her really work on Sunday?

 

[VryBigPP]

Park it and see mechanic tomorrow as you say.
Does he/her really work on Sunday?

I was skeptical too, but they did indeed confirm over the phone they’re open on a Sunday, pleasantly surprised.

Anyway, I’ve had the idea I could be overreacting and it could potentially be condensation from the AC being on, currently parked and idling with the AC off to see if I can still observe any leaks, if not will idle with AC on and see if that could be just that hopefully.

Even if it was just the AC condensation as normal, doesn’t explain the bubbling noise coming from the reservoir area, possibly air trapped inside after being replaced? Who knows, I’ll report back if anything comes up

 

[Skylarking]

Radiators just don't seem to last like they used to

Anyway, in old cars, if changing just the radiator, you sometimes (rare) saw leaks around the old hose junction at the new radiator spout because the old hoses are perishing. So when installing a new radiator, it's a really good idea to also replace the hoses and clamps. That way you can be sure nothing should leak and no old hose will burst a year or so later. Probably still holds true with new cars

Why it's leaking in the same spot is interesting. I'd hope the mechanic isn't a shady fellow that charged you for a new rad and just cleaned up the old one and reinstalled. And if it's ac condensation you are seeing now, was it ac condensation in the first instance? May be all you really needed was a new oem radiator cap (a known failure point). So I'm wondering how the root cause of the overheating was actually diagnosed

The other issue is that the VE/VF is supposedly a pain to get all the air out of the cooling system when doing a coolant flush/change. You really need to have a funnel that screws into the radiator cap so it can be filled with coolant so the leval at the radiator is at a higher level that the block/heads. Then you need to start the engine and run it until it gets to temp so the termostat opens and then blip the revs 2k - 3k rpm to burp the air out of the engine.

Shops use a vacuum bleed system which should make it much easier to get all the air out... but from what i've read, sometimes they fook up... In any case, you'd think they'd run the engine to temp. let it cool down until its safe to remove the radiator cap and then check coolant level in teh radiator before pressure testing the system as final confirmation that the leak has been fixed.

PS: @Fu Manchu did a nice thread on how to change the coolant, see below:

[VZ] - VZ VE VF Alloytec Cooling System Repairs

Helpful basic overview: The following is for both VZ and VE and VF Alloytec motors. The first part of this is on my VZ. Opened the bonnet only to discover a fine line of pink spray from the dry red coolant, all across the engine bay. Lucky to catch it before it let go all together, and no...

forums.justcommodores.com.au

 

[VryBigPP]

Radiators just don't seem to last like they used to

Anyway, in old cars, if changing just the radiator, you sometimes (rare) saw leaks around the old hose junction at the new radiator spout because the old hoses are perishing. So when installing a new radiator, it's a really good idea to also replace the hoses and clamps. That way you can be sure nothing should leak and no old hose will burst a year or so later. Probably still holds true with new cars

Why it's leaking in the same spot is interesting. I'd hope the mechanic isn't a shady fellow that charged you for a new rad and just cleaned up the old one and reinstalled. And if it's ac condensation you are seeing now, was it ac condensation in the first instance? May be all you really needed was a new oem radiator cap (a known failure point). So I'm wondering how the root cause of the overheating was actually diagnosed

The other issue is that the VE/VF is supposedly a pain to get all the air out of the cooling system when doing a coolant flush/change. You really need to have a funnel that screws into the radiator cap so it can be filled with coolant so the leval at the radiator is at a higher level that the block/heads. Then you need to start the engine and run it until it gets to temp so the termostat opens and then blip the revs 2k - 3k rpm to burp the air out of the engine.

Shops use a vacuum bleed system which should make it much easier to get all the air out... but from what i've read, sometimes they fook up... In any case, you'd think they'd run the engine to temp. let it cool down until its safe to remove the radiator cap and then check coolant level in teh radiator before pressure testing the system as final confirmation that the leak has been fixed.

PS: @Fu Manchu did a nice thread on how to change the coolant, see below:

http://[URL]https://forums.justcomm...ve-vf-alloytec-cooling-system-repairs.279976/

[/URL]

My regular mechanic is solid, saw the old radiator out for myself, so it shouldn't be that.

I'll have to hit up the mechanic I've lined up for tomorrow, or see my regular on Monday, after idling for 40 mins (20 with AC on, 20 without), I was unable to observe any sort of leak apart from an unrelated condensation leak coming from the exhaust gasket, which I'll address in due time. Apart from that, no temperature fluctuations, no odd noises, and nothing out of the ordinary. It very well could have been AC condensation in the first instance, I can't confirm for certainty but it very well may have. I'm carrying some extra red coolant in the car whenever I need to drive in the event anything goes wrong and the coolant does indeed start leaking.

You're absolutely right about the radiator cap, and I'll question about that when I take it to my mechanic. I'll be taking it anyway to see if I can get an explanation for the boiling/bubbling noise from the reservoir, which is hopefully trapped air and not anything more severe, such as a blown head gasket.

 

[Fu Manchu]

It will be air coming out after the system was opened. The reservoir would have been filled and the level drops as the air comes out.

The coolant drip could have been from the repair if they never washed it down after.

Wash the area down with clean water and see if coolant forms again.

Ideally the air is bled out properly as per the linked thread posted already.

 

[stooge]

to see if I can get an explanation for the boiling/bubbling noise from the reservoir, which is hopefully trapped air and not anything more severe, such as a blown head gasket

It will just be the system doing what it is designed to do which is self bleeding.
If you want to speed it up just wait until it is cold and pop the radiator cap off and top it up.
Make sure you keep the reservoir topped up too so it does not suck air back into the system.

If you are worried that it might be a gasket just get your mechanic to pressure test the system and you will quickly find out if it is leaking and if there is no visible coolant leak then it might be a gasket.