Perkins V8.510 overheating on one side. Advice please...

damNatives

New User
Hi,

I don't have a Massey Ferguson, but I know that the Perkins V8 is found in one or two and I'd be keen to get some advice. Mine is in a 1976 Seddon bus.

It starts and idles well. The right hand head heats more than the left but does not overheat at idle. It does overheat when taken out on the road (about 15km at 80km/hr and it starts to steam).

I'd like to know which causes to investigate first (and how to investigate them). My mechanic wants to rod the radiator in case it's blocked, but it seems to me that I should concentrate on one side because it's overheating on one side. I have read online about a Perkins V8.510 overheating on the right hand side because the exhaust manifold was blocked. I guess the other prime suspect is the head gasket.

I'd appreciate any advice. Unfortunately, the bus is 5hrs drive away so I can't check much more and can only instruct the mechanic.

TIA
Glen
 
There is a separate thermostat for each head (on
Massey applications). Aside from that, I would check
the radiator for combustion gasses. ie. leaking head
gasket. If this started all of a sudden, i would
doubt the radiator.
 
Thanks for the reply. I should have mentioned that I have removed the thermostat from the overheating side. I also checked that there was a flow of coolant on that side. Seems unlikely for the radiator or water pump to be the culprit when it's only overheating on one side but someone might correct me on that.

Checking the coolant for combustion gases seems like a good idea to me. I wouldn't have thought of a blocked exhaust manifold if I hadn't read about it, but that is probably the next thing I'll check.
 
seen a bus do that with a 318 detroit it broke a belt ran hot enough to lose part of the water once the belt was replaced it would start to heat up even though the radiator was full it had a split radiator system and filled from one only, engine had 2 pumps after a little while someone asked if bleeding the thermostat might help they opened the bleeder sure enough it was airlocked immediately the water level went down topped it off problem solved
 
If you suspect a blocked exhaust to the extent of overheating manifold vacuum sould drop. I would get a vacuum gauge and run the engine unloaded at 2,500 RPM for a few minutes to see if the vacuum signal slowly starts to drop. It should hold steady. Secondly, there is a dye test (combustion leak tester) we use to verify the presence of exhaust gasses in the coolant. It starts out blue and turns to yellow if there is gasoline exhaust gas present. Any repairs recently? Gerard
 
So is it possible that you had a bad thermostat on one side and then by removing it, you have prevented closure of the bypass (thus perpetuating the overheat)? Remember that in 95% of all thermostat installations, when the t-stat opens it not only allows coolant to flow to the rad but ALSO THEN BLOCKS THE BYPASS!

If the exhaust is not plugged, then I would try and boil the old thermostat to see if it opens...

Regards,
 
Since you have the thermostat out, and if you can see the coolant in the radiator fire it up, and look for bubbles in the coolant. You can also pressurize the cooling system, and see if it leaks down (maybe even pull the injectors from that side if you pressure test the cooling system) put a piece of hose to your ear, and the other end to where the injectors were, and listen for air leaking if it's leaking down. You maybe even be able to see coolant entering the cylinder by looking in through the holes for the injectors.
 
(quoted from post at 15:55:00 11/10/14) seen a bus do that with a 318 detroit it broke a belt ran hot enough to lose part of the water once the belt was replaced it would start to heat up even though the radiator was full it had a split radiator system and filled from one only, engine had 2 pumps after a little while someone asked if bleeding the thermostat might help they opened the bleeder sure enough it was airlocked immediately the water level went down topped it off problem solved

Will be sure to check whether thermostat needs bleeding when fitted (see below). Cheers
 
(quoted from post at 00:58:06 11/11/14) If you suspect a blocked exhaust to the extent of overheating manifold vacuum sould drop. I would get a vacuum gauge and run the engine unloaded at 2,500 RPM for a few minutes to see if the vacuum signal slowly starts to drop. It should hold steady. Secondly, there is a dye test (combustion leak tester) we use to verify the presence of exhaust gasses in the coolant. It starts out blue and turns to yellow if there is gasoline exhaust gas present. Any repairs recently? Gerard

Hi Gerard, no repairs recently. It has been sitting for a few years, apart from the odd run. I bought it a few months ago.

Current plan is to:

1) Check for bubbles in the coolant. If seen, I'll get some of that combustion leak tester to confirm (and then remove the head I guess). If not...
2) Fit a new thermostat. If this doesn't fix the problem...
3) Drill a hole in the exhaust (between the manifold and the muffler?), fit a vacuum gauge and test as you suggest. If pressure drops, I'll pull the manifold off. If signal holds steady...
4) Combustion leak test. If dye stays blue, I guess I'll reconsider the radiator and water pump.

Thanks very much for the help.
 
(quoted from post at 03:12:15 11/11/14) So is it possible that you had a bad thermostat on one side and then by removing it, you have prevented closure of the bypass (thus perpetuating the overheat)? Remember that in 95% of all thermostat installations, when the t-stat opens it not only allows coolant to flow to the rad but ALSO THEN BLOCKS THE BYPASS!

If the exhaust is not plugged, then I would try and boil the old thermostat to see if it opens...

Regards,

Yup, quite possible that the unblocked bypass is contributing to the problem. Hadn't thought of that. Old thermostat was had it and in pieces. I'll fit a new thermostat as above and here's hoping! Cheers.
 
(quoted from post at 05:00:30 11/11/14) Since you have the thermostat out, and if you can see the coolant in the radiator fire it up, and look for bubbles in the coolant. You can also pressurize the cooling system, and see if it leaks down (maybe even pull the injectors from that side if you pressure test the cooling system) put a piece of hose to your ear, and the other end to where the injectors were, and listen for air leaking if it's leaking down. You maybe even be able to see coolant entering the cylinder by looking in through the holes for the injectors.

Will check for bubbles as above. Pressure tester is an alternative to the dye, I'll keep it in mind and ask around to see if I can borrow one. Thanks!
 
I've read lots of forums to get information before, but this is the first time that I've posted a question. I'm very glad that I did. Especially after getting a text from my mechanic that he has been offered a lot of work and now can't look at it until at least January.

I'll drive up and give it a crack myself. Kinda looking forward to it. Thanks to all.
 
Kinda late posting my results but...

All advice was gratefully received and on the
money.

Tested temperature gauges, one was faulty and
infrared thermostat revealed both sides
overheating.
Pressure check revealed hole in radiator and
leak from thermostat housing around bolt head.
Upside down soft drink bottle revealed no
stream of bubbles.
Radiator removed, rodded, cleaned, welded and
painted.
Water pump removed and checked.
Thermostat housing fixed with JB Weld.
New gaskets cut.
Two new thermostats fitted.
Water pump and radiator refitted.
Flushed and anti-corrosive added to the
coolant.

Goes a charm.

Thanks again!
 

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