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Any suggestions?
JeffHs - 17/9/21 at 05:11 PM

Sudden overheating on Pinto. Has been running fine for years on Polo rad and remote expansion tank. Must be thermostat I assumed so ordered one from Burton.
Took off the stat housing and the old stat fell out. No sign of the retaining spring. Had as good a look as is possible in the head, nothing.
Fitted new stat with new ring. If anything worse so concluded it must be water pump. Nothing wrong with pump except the impeller looks a bit secondhand. Again no sign of the ring or any bits. Refitted pump. Took off stat housing again and found a sharp bit in a vertical passage
between the head and the pump.
Pulled it out with pliers, about a third of the old spring ring.
No idea where the rest is.
What should I do next?

RedAvon - 18/9/21 at 07:11 AM

Only way I can think of, which is how I would tackle it, is to keep all the bits I find until I know I have the complete unit. Maybe compare with the replacement so I know I have everything.

Then it's a matter of dismantling pipe work, flushing, using a magnet, using a cheap Aldi flexible camera scope, various round gallery brushes etc. until you have retrieved all the original parts.

With enough flushing force and patience it should be possible.

Good luck!

Ian

Mr Whippy - 18/9/21 at 08:34 AM

Blocked rad or an airlock, not much else to go wrong. Is the oil and coolant clean?

adithorp - 18/9/21 at 10:02 PM

quote:
Originally posted by Mr Whippy
Blocked rad or an airlock, not much else to go wrong. Is the oil and coolant clean?


Have you read the OP?

adithorp - 18/9/21 at 10:05 PM

JeffHs, two choices... Either strip down and 'head off and search for the missing bits. Or run it as is and hope it's OK. Personally I'd go option 2.

pigeondave - 19/9/21 at 12:34 AM

quote:
Originally posted by adithorp
JeffHs, two choices... Either strip down and 'head off and search for the missing bits. Or run it as is and hope it's OK. Personally I'd go option 2.


Yeah go with option 2, if it goes pop its time to upgrade

[Edited on 19/9/21 by pigeondave]

adithorp - 20/9/21 at 07:52 AM

Thinking about option 2 (suck it and see)...
1, The missing bits could get stuck somewhere the obstruct flow. Probably unlikely as it's unlikely in the water jacket they could make much difference and in the rad unless they got stuck right in the inlet they'd not block enough tubes to be an issue.
2, They get stuck in the (new) 'stat but that'd wedge it open and you'd get overcooling which while not good isn't the critical issue that overheating would be. Suppose there's a tiny chance of wedging it shut but unlikely.
3, It jams the water pump but the flow there is into the block so it'd have to either go against that or get through the rad (and anything small enough to do that won't effect the pump).

Given that the missing bits probably don't float I think they're most likely to just sit in the bottom of the water jacket. somewhere

JeffHs - 20/9/21 at 09:00 AM

Thanks for the advice. I'd decided to suck it and see. I checked both thermostats. Although they're both 88 degrees, the old one opens sooner so I put that in and went for a short drive. Still overheating, well into the red but not off the scale as it was before and no water loss this time. I took the whole cooling system to bits and back flushed everything. Checked all the sludge with a magnet and some metallic bits were found but nothing bigger than filings.
Had a closer look at the water pump and compared it with photo of new impeller. There is substantial tip damage so I guess it's eaten the remains of the spring? New pump on order so I'll try that before I take the head off. In the meantime I'll remove the inlet manifold and flush through from the port there.

jollygreengiant - 22/9/21 at 07:22 AM

quote:
Originally posted by JeffHs
Thanks for the advice. I'd decided to suck it and see. I checked both thermostats. Although they're both 88 degrees, the old one opens sooner so I put that in and went for a short drive. Still overheating, well into the red but not off the scale as it was before and no water loss this time. I took the whole cooling system to bits and back flushed everything. Checked all the sludge with a magnet and some metallic bits were found but nothing bigger than filings.
Had a closer look at the water pump and compared it with photo of new impeller. There is substantial tip damage so I guess it's eaten the remains of the spring? New pump on order so I'll try that before I take the head off. In the meantime I'll remove the inlet manifold and flush through from the port there.


It could be just as simple as the temperature sender unit going faulty, Is it the standard temp gauge or an ADD ON supplementary unit. IF it's a standard type, it could just be the sender unit going faulty (when this happens, they do tend to read high, before total failure). For the cost of one, it is a cheap check and you will need no gaskets.