v8 water problem

B

bri p6b v8

New Member
Hi all just asking 4 sum advice,i have a v8s with 34000 miles fully documented.I am having sum water problems wiv it,it had a little leak under the inlet manifold so i added sum liquid sealent stuff to the coolant,(worst thing i have ever done)and it fixed the leak but now if i take her out 4 a little run and cum back i have water coming out of the overflow pipe it is foamyish,and it is starting to overheat, i have flushed the system out and it is still doin it but i dnt think all that stuff is out the system yet,the performance of the car isnt down it pulls like a train,there is no mayonaise in the oil or water,i just hope i havent done any damage to the cylinder head gaskets.I am thinking of taking the radiator off and getting it recored any advice would be well appreciated thanks for reading Bri
 
Hi Bri,

Is the radiator return from the manifold clear? i.e. the hose from here:


to the radiator neck. With the cap off you should see water flowing back into the rad. If not use a 3mm drill to clear the metal pipe.

Before you think about a recore, drain down the system (don't forget the 2 cylinder block taps) and take the rad out. Reverse flush that whilst giving it a good shake, and flush the heater out too. Refit the rad, close the block taps, and refill. I'd do this with plain water, give it a brief run up to temperature, cool and drain it a couple more times before finally filling with the right antifreeze mixture, and topping up to the level whilst running with the cap off.

Your leak under the manifold could be coming from the thermostat housing..if so while it's drained have that off and fit a new gasket..and I'd renew the stat while it's out. Or it could be just a hose.

Good luck...let us know how you get on! :)
 

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does your manifold have the pipes running under the manifold? they can rust and become become porous.

Colin
 
vaultsman said:
Hi Bri,

Is the radiator return from the manifold clear? i.e. the hose from here:


to the radiator neck. With the cap off you should see water flowing back into the rad. If not use a 3mm drill to clear the metal pipe.

Before you think about a recore, drain down the system (don't forget the 2 cylinder block taps) and take the rad out. Reverse flush that whilst giving it a good shake, and flush the heater out too. Refit the rad, close the block taps, and refill. I'd do this with plain water, give it a brief run up to temperature, cool and drain it a couple more times before finally filling with the right antifreeze mixture, and topping up to the level whilst running with the cap off.

Your leak under the manifold could be coming from the thermostat housing..if so while it's drained have that off and fit a new gasket..and I'd renew the stat while it's out. Or it could be just a hose.

Good luck...let us know how you get on! :)
Click to expand...


Hi vaultsman, i have had a 3mm bit in there and it all seems clear,i am goin to drain all the system again at the wkend,take the rad off and back flush it,hopefully that mite wrk,i am actually running the car without a thermostat in as i only eva use it 4 shows in the summer,do u think that would make a difference? cheers Bri
 
arthuy said:
does your manifold have the pipes running under the manifold? they can rust and become become porous.

Colin
Click to expand...


Hi Colin yes my car does have a water pipe running under the inlet manifold but i had all that off bout 4 month ago and had every thing powdercoated,it doesnt leak anymore,cheers Bri
 
Did it only start overheating when you added the leak sealant ? Strange . I used to put in a bottle just for luck and it would froth up in the radiator but it made no difference to the running temperature
 
It's very easy when you first notice a problem to start ascribing all sorts of other things to the same cause. It might be a good idea to break your problems down into separate items and consider possible causes for each.

First off the coolant loss under the inlet manifold. Clearly only a small leak. I think I might start by renewing all hoses that could leak into that area. You have low mileage but age is significant for rubber as well as usage. That would include all the heater hoses. Anything else that might leak in that area - the thermostat housing gasket has been mentioned already, as well as corrosion of the pipes in the V. Then I might get a gas analysis of the (by now pretty fresh) coolant just to eliminate the possibility of a failing head gasket (or at least eliminate it failing between the cylinders and coolant!). All those done, I'd sit back and wait for more positive signals as the fault develops! As an aside, head gaskets in general on old low mileage cars are prone to failure when the usage of the car then increases. It's the old adage that one of the worst things you can do with a bit of machinery is not to use it!

Next the coolant loss from the overflow. All P6B's do this to a greater or lesser extent. It may be that you are now noticing it for the first time having become super sensitive about topping up the radiator because of the leak. In my recollection coolant level left untouched tends to settle at just about the top of the core static. The fix for this is to fit a coolant header tank connected to the overflow, with a blank cap on the rad and the pressure cap on the overflow tank.

Overheating. Well the P6B is undercooled. If you stand in traffic on a hot day, especially just after a bit of a blast, you should expect it to overheat. Think back to your recent trips and see if they fit this pattern. Again an easy fix - get the rad recored with a three row core instead of a two row. Could your fan belt be slipping slightly - your mileage is about right to require first renewal due to glazing of the working surface; and it is made of rubber! After that either a supplementary electric fan or completely replacing the engine driven fan with electric fan(s) is a good idea.

Hope that helps keep things in perspective.

Chris
 
chrisyork said:
It's very easy when you first notice a problem to start ascribing all sorts of other things to the same cause. It might be a good idea to break your problems down into separate items and consider possible causes for each.

First off the coolant loss under the inlet manifold. Clearly only a small leak. I think I might start by renewing all hoses that could leak into that area. You have low mileage but age is significant for rubber as well as usage. That would include all the heater hoses. Anything else that might leak in that area - the thermostat housing gasket has been mentioned already, as well as corrosion of the pipes in the V. Then I might get a gas analysis of the (by now pretty fresh) coolant just to eliminate the possibility of a failing head gasket (or at least eliminate it failing between the cylinders and coolant!). All those done, I'd sit back and wait for more positive signals as the fault develops! As an aside, head gaskets in general on old low mileage cars are prone to failure when the usage of the car then increases. It's the old adage that one of the worst things you can do with a bit of machinery is not to use it!

Next the coolant loss from the overflow. All P6B's do this to a greater or lesser extent. It may be that you are now noticing it for the first time having become super sensitive about topping up the radiator because of the leak. In my recollection coolant level left untouched tends to settle at just about the top of the core static. The fix for this is to fit a coolant header tank connected to the overflow, with a blank cap on the rad and the pressure cap on the overflow tank.

Overheating. Well the P6B is undercooled. If you stand in traffic on a hot day, especially just after a bit of a blast, you should expect it to overheat. Think back to your recent trips and see if they fit this pattern. Again an easy fix - get the rad recored with a three row core instead of a two row. Could your fan belt be slipping slightly - your mileage is about right to require first renewal due to glazing of the working surface; and it is made of rubber! After that either a supplementary electric fan or completely replacing the engine driven fan with electric fan(s) is a good idea.

Hope that helps keep things in perspective.

Chris
Click to expand...

Cheers chris york,i have renewed every pipe on the engine ,and it doesnt seem to leak now,i have renewed the fan belt.All this bother has started since i put that stuff in,i am goin to have another go at flushing the system out at the weekend and if no success am goin to get the rad recored thanks 4 your advice,well appreciated Bri
 
Just an idea hiding in the back of my mind....

Fill the cooling system with a 50/50 mix of vinegar and water and run it up to temperature. I used it on my Mini years back to descale the insides. I don't know how effective it was, but it made a difference so maybe it will shift that gunk.
 
Hi all just to let u all no,i have had the rad off today flushed it all out and still the same,so i have took waterpump off there is a little bit of play bt not alot,my rad has been sent off 4 a recore and have opted for 3 cores instead of the 2, and have orded a waterpump just to be on the safe side,running the car 2day temp went nearly to red then came bk 2 half,felt the rad and the rad was hot at the top and only warmish at the bottom need my car ready soon because i am going to the piece hall with it.is any 1 goin?Cheers Bri
 
Nobody's mentioned the thermostat yet... Temperature rising then dropping suggests that it could be sticking, maybe as a result of the stop leak stuff.
 
KiwiRover said:
Nobody's mentioned the thermostat yet... Temperature rising then dropping suggests that it could be sticking, maybe as a result of the stop leak stuff.
Click to expand...
Hi there,i have removed the thermastat completeley, so i am running it without 1 in,cheers Bri
 
DaveHerns said:
Could be an airlock . so it might be OK once that clears
Click to expand...
Hi Dave,i shud have all my new bits here by wednesday,new water pump,3 cored recon rad,new rad cap and a new thermostat,i hope that will fix it cos its cost an arm and a leg ha,wats the correct way to bleed the system?thanks 4 the interest Bri
 
Bri wrote,..
wats the correct way to bleed the system?
Click to expand...

Hello Bri,

Once it is all back together, fill the radiator with coolant, start the engine,..the coolant level will fall markedly,..continue adding coolant until the level stabilises at the base of the filler neck. Put on the radiator cap and go for a drive. Air trapped within the system will gradually make its way into the radiator and as a consequence the coolant level will fall slightly. Generally it may take a couple of days for the system to fully settle. After that time with the engine cold remove the radiator cap, start the engine and top up the coolant to the base of the filler neck while maintaining a fast idle,..say 1500 rpm. Replace radiator cap.
All done.

Ron.
 
Hi all,i have fitted the new rad 3 core,fitted new waterpump and thermostat and the new rad cap,the car is running dare i say lovely again, let it tickover 4 a gud 20 mins and no leaks and temp stoppin in the the 1st quarter,although i have not took it 4 a run yet as my seat is away getting retrimmed,will let u all no as soon as i get the seat back,thank u all 4 all the helpful hints and tips,thanks again Bri
 
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