3VZ strange overheating issue just

[smash]

So I'm going to Spa next week and I want to take the Ferota but it's really trying it's best not to go!

Today it's decided to develop a couple of new faults - this one revealed itself in traffic queue.

Stationary in queue temp gauge rose steadily to 3/4 at which point I panicked and opened heater matrix, stuck heater fan on and rev'd engine to about 2k

Within a couple of seconds the temp gauge suddenly plummeted to normal. Same thing happened again after I'd turned the heater fan off - but reving the engine gave the almost instant temperature drop again. Normal running temp for the car is somewhere just under halfway. temp stays down when on the move

Haven't started fault finding yet but would appreciate any suggestions for likely culprits!

[cdwood2010]

Panic not, this is a known issue.

A pattern water pump doesnt move enough water around at tickover, but its fine when running at a higher rev.

The Totty one seems to work just fine. Any idea what water pump youre using?

Chris.

[smash]

Ah OK - thanks for prompt response btw! The pump should be whatever was fitted by Woodsport at time of conversion - weird it has never done this before though.

[cdwood2010]

Yes I think Paul discovered this by comparing swaps. Something to do with the number of fins on a water pump.

If you rev the engine occasionally it should shift the water around enough to keep things normal.

Paul should be able to confirm what water pump would have been fitted, just in case I'm talking plop!

C.

[cdwood2010]

Oh and here's the original thread about it....

V6-water-pump-discovery!
http://www.twobrutal.co.uk/forum/showthread.php?t=15423

[smash]

Ah-ha! So I have an 'orrible Quetin pumping water round me lump!!

Yep the symptoms on that thread are exactly what is going on - I guess it's the first time I've been stuck in traffic (there was an accident so stationary for a long time) on a reasonably hot day. Well it can get hot under the collar all it wants - it's not getting a new pump before Spa!

[cdwood2010]

I wouldn't sweat it (see what I did there?)

If (god forbid) you get stuck in traffic, turn your engine off.

Simples.

:)

[aussiemr2]

I have been having the same problem but I certainly have a genuine Toyota pump in mine
Turns out I have a massive airlock as you can hear it gurgle after turning engine off

[briweekes]

Appreciate this is an old thread. Thrillseeker discovered a common issue with the top hose running from the rad cap, over the top of the engine and forwards from there. Air accumulates at the top curve of this pipe. Cutting and fitting a small alloy tube with a vent hole at the top (bolt hole), allows air to be vented out. Works a treat. I had the same issue, fixed today.

[Paul Woods]

On 200+ V6 swaps i've never seen this issue, the filler point is the highest coolant point in the engine bay, so all air rises to that point and gets purged to the expansion bottle during cooldowns.

If you're seeing air trapped in the pipe coming from the filler point then it must have a funny angle on it making it the highest point for the air to get trapped.

Air will always find the highest point, and can be confirmed by unscrewing the pressure cap on a cold engine, there should always be coolant visible, furthermore having a very small pocket of trapped air in a small section of pipe on top of the engine is definitely not going to cause an overheating issue, it just won't, there must be another problem lurking or cooling system issue.

I'm all for fixes and cures, but you have a factory bleed point less than 6" away from that one.... so i would be looking elsewhere if you're having issues.