Are you sure the radiator bleed pipe is clear? The small one from the radiator to the neck of the expansion bottle.. take it off the radiator, take the cap off and blow down the pipe r reconnect
With the engine running at 2000rpm you should get a good flow of water returning if you look into the neck. It should still dribble at idle
With the engine running at 2000rpm you should get a good flow of water returning if you look into the neck. It should still dribble at idle
ar1g3
Well-Known Member
Yeah I've blown that out multiple times.
Will I get a stream of coolant through that pipe if there's an airlock?
If the top hose has coolant in it then yes.
If it's empty then you need to burp it.
I've found if it's really stubborn you're best draining and starting again. Fill it slowly, a small jug can help. Listen out and you'll start to hear it glug, when it does this, finger over the bleed hole and squeeze the top hose a few times you'll hear it wheeze and the level drop. Fill some more, repeat
If it's empty then you need to burp it.
I've found if it's really stubborn you're best draining and starting again. Fill it slowly, a small jug can help. Listen out and you'll start to hear it glug, when it does this, finger over the bleed hole and squeeze the top hose a few times you'll hear it wheeze and the level drop. Fill some more, repeat
ar1g3
Well-Known Member
There's no flow going through the bleeding line back to the header tank. If I squeeze the top hose there's gurgling.
I'm going to replace the water pump even though I don't know if it's bad or not. It's not expensive and seems reasonably easy to do. The car has been sitting for 10 years so maybe it's a good idea anyways.
I'm going to replace the water pump even though I don't know if it's bad or not. It's not expensive and seems reasonably easy to do. The car has been sitting for 10 years so maybe it's a good idea anyways.
If you can feel water in the top hose then it should spill out when you take the bleed pipe off.
If it doesn't then you've a blockage, you should be able to poke something up there eg wire.
Some DIYers love to use bath sealer instead of gaskets, bits break off inside and cause problems like this. Ask me how i know
If it does then yes the pump might be bad. Metal ones can rust, plastic ones can break. Metal ones are still better
If it doesn't then you've a blockage, you should be able to poke something up there eg wire.
Some DIYers love to use bath sealer instead of gaskets, bits break off inside and cause problems like this. Ask me how i know
If it does then yes the pump might be bad. Metal ones can rust, plastic ones can break. Metal ones are still better
P38 Monkey
Well-Known Member
Bath (silicone) sealant - yep..!!! Makes its way round to the rad bleed pipe and blocks it at the header tank end.. steam results.If you can feel water in the top hose then it should spill out when you take the bleed pipe off.
If it doesn't then you've a blockage, you should be able to poke something up there eg wire.
Some DIYers love to use bath sealer instead of gaskets, bits break off inside and cause problems like this. Ask me how i know
If it does then yes the pump might be bad. Metal ones can rust, plastic ones can break. Metal ones are still better
ar1g3
Well-Known Member
Solved it!!
Water pump was not damaged, was one with a brass pump wheel so I'm keeping it as a spare. Probably not necessary to have changed it. It was indeed glued in with loads of silicone/RTV. I don't think changing it was what solved my issue.
On recommendation of a friend I did not fill the system from the header tank. I disconnected the top radiator hose and filled both the block and the rad up from there. I think that's what solved it. Bit of bubbles after start up but nothing like before. Solid stream from the bleed pipe now. Top hose still gurgling slightly when I squeeze it but I think that will solve itself after a bit of running.
I think that's a top tip for all V8 owners: fill the coolant from the top rad hose and not from the header tank.
Also I managed to change the water pump including doing a thread insert while only losing about 1,5l of coolant. Hose clamping pliers are really something every DIY mechanic should get. I clamped up the top hose, the hose towards the pump, the hose towards the throttle body and 1 of the heater core hoses. By keeping the system airtight like this it didn't drain completely.
Reason I did this was because I had just replaced the coolant.
Thanks for the help and advice everyone!
Water pump was not damaged, was one with a brass pump wheel so I'm keeping it as a spare. Probably not necessary to have changed it. It was indeed glued in with loads of silicone/RTV. I don't think changing it was what solved my issue.
On recommendation of a friend I did not fill the system from the header tank. I disconnected the top radiator hose and filled both the block and the rad up from there. I think that's what solved it. Bit of bubbles after start up but nothing like before. Solid stream from the bleed pipe now. Top hose still gurgling slightly when I squeeze it but I think that will solve itself after a bit of running.
I think that's a top tip for all V8 owners: fill the coolant from the top rad hose and not from the header tank.
Also I managed to change the water pump including doing a thread insert while only losing about 1,5l of coolant. Hose clamping pliers are really something every DIY mechanic should get. I clamped up the top hose, the hose towards the pump, the hose towards the throttle body and 1 of the heater core hoses. By keeping the system airtight like this it didn't drain completely.
Reason I did this was because I had just replaced the coolant.
Thanks for the help and advice everyone!
P38 Monkey
Well-Known Member
Not such a good outcome on my P38 cooling system - overheated when some silicone sealant (that invention of the devil) blocked up the rad bleed pipe at the header tank end. Blockage cleared and system refilled, but now it defo has exhaust gas in it.
The RELD blue dye test indicated gas, and the simple smell test confirms it.
Now I am trying to find a local garage that will replace the head gasket - not sure whether to get both done at the time - engine has done around 90k miles.
Just have to hope that the heads are not warped and there is no shifting of the liners... Fingers crossed.
The RELD blue dye test indicated gas, and the simple smell test confirms it.
Now I am trying to find a local garage that will replace the head gasket - not sure whether to get both done at the time - engine has done around 90k miles.
Just have to hope that the heads are not warped and there is no shifting of the liners... Fingers crossed.
P38 Monkey
Well-Known Member
The temp gauge shot up and red light came on, but it didn’t lose all its water - I think about 2-3 litres was dumped. No steam gushing either. Fingers crossed…!
Do both.
It isn't a bad job but it does take time, especially the exhaust bolts which tend to be seized,. especially the heat-shield ones. We ended up just chiselling them off and using exhaust wrap on reassembly.
Take one weekend to pull it apart and then check what you need for reassembly and order the parts. Put it back together the following weekend.
fingers crossed indeed
i'd say upgrade to head studs while you're at it, but thats a lot of money if you find the block has already suffered
ar1g3
Well-Known Member
Really would surprise me if there's a blockage because I flushed it out with tap water. I also blew it out with compressed air through the outlet of the heater core, quite thoroughly. (I changed coolant types). But I think that may have been the issue. I blew every last drop of coolant out, probably blowing air into parts which normally never really drain.
I will definitely keep a close eye on the temp guage! And I'll check coolant flow through the bleed pipe from time to time.
Oh my that doesn't sound fun.. Based on what I've heard the liners is something that is more likely to happen on high-mileage blocks. Of course this is hearsay so don't quote me on it...
Why not attempt the head gaskets yourself? It's a relatively easy engine to do it on because of the pushrod design. No messing about with timing etc.
P38 Monkey
Well-Known Member
90k miles on the engine…
I am 76, so considerably more mileage than my P38. Garages seem less than keen to do it - I think they like servicing newer cars. Might well end up doing it.
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