Overheating

[BongoDaz]

Hi, Im pulling my hair out, i had a brand new head fitted about 3 weeks ago, as the mechanic took the old one off, pressure tested it and it was cracked, new head fitted and the Bubbling in the header tank was still present and pressure was building up still, the pipe at the top of the radiator kept getting rock hard with pressure, the pipe at the bottom of the rad split, changed that, mechanic bleed the system, still the same, changed the rad for a new one, still the same, the head was then tightened down further, seemed to fix it, well so we thought, now its back the same, it will run on normal temp for a while, then every now and then gauge will run high to hot, and go back down again, open the header tank and water and coolant will pulsate from the tank, the mechanic is now thinking about tanking the head back off again and fitting another new gasket, any suggestions ?

[Velocette]

Hi, Im pulling my hair out, i had a brand new head fitted about 3 weeks ago, as the mechanic took the old one off, pressure tested it and it was cracked, new head fitted and the Bubbling in the header tank was still present and pressure was building up still, the pipe at the top of the radiator kept getting rock hard with pressure, the pipe at the bottom of the rad split, changed that, mechanic bleed the system, still the same, changed the rad for a new one, still the same, the head was then tightened down further, seemed to fix it, well so we thought, now its back the same, it will run on normal temp for a while, then every now and then gauge will run high to hot, and go back down again, open the header tank and water and coolant will pulsate from the tank, the mechanic is now thinking about tanking the head back off again and fitting another new gasket, any suggestions ?

thermostat?

[Northern Bongolow]

with the engine not running, fill up the coolant the best you can then pressure test the system to approx 1 bar, then look for leaks and repair if ness.
did the water pump get changed when the head was swapped,these leak but are hard to spot as they can leak from the telltale hole at the 6 oclock position, this leak goes undetected behind the crank pulley.

[Simon Jones]

My suggestion would be to have a read of some of these threads, especially my findings regarding 'decking the block' and WellSeal head gasket sealer:

http://igmaynard.co.uk/bongo/forum/sear ... hor_id=936

[BongoDaz]

Hi, Im pulling my hair out, i had a brand new head fitted about 3 weeks ago, as the mechanic took the old one off, pressure tested it and it was cracked, new head fitted and the Bubbling in the header tank was still present and pressure was building up still, the pipe at the top of the radiator kept getting rock hard with pressure, the pipe at the bottom of the rad split, changed that, mechanic bleed the system, still the same, changed the rad for a new one, still the same, the head was then tightened down further, seemed to fix it, well so we thought, now its back the same, it will run on normal temp for a while, then every now and then gauge will run high to hot, and go back down again, open the header tank and water and coolant will pulsate from the tank, the mechanic is now thinking about tanking the head back off again and fitting another new gasket, any suggestions ?

thermostat?

Yeah that was changed, thanks for the reply

[BongoDaz]

with the engine not running, fill up the coolant the best you can then pressure test the system to approx 1 bar, then look for leaks and repair if ness.
did the water pump get changed when the head was swapped,these leak but are hard to spot as they can leak from the telltale hole at the 6 oclock position, this leak goes undetected behind the crank pulley.

Thanks for the reply, i thought Water Pump, he said it was ok, but now you have said that im not to sure

[Titan1995]

Was the thermostat an original or pattern part?

Tightening the head down further should not make any difference if correct sequence was followed originally. Having stretch bolts fitted. Oh did they get replaced at the same time?

54 torques and angles.

[BongoDaz]

Was the thermostat an original or pattern part?

Tightening the head down further should not make any difference if correct sequence was followed originally. Having stretch bolts fitted. Oh did they get replaced at the same time?

54 torques and angles.

thanks for your reply, i will find out about the Thermostat, hes taking the head back off Thursday, fingers crossed

[BongoDaz]

My suggestion would be to have a read of some of these threads, especially my findings regarding 'decking the block' and WellSeal head gasket sealer:

http://igmaynard.co.uk/bongo/forum/sear ... hor_id=936

Thanks Simon

[BongoDaz]

with the engine not running, fill up the coolant the best you can then pressure test the system to approx 1 bar, then look for leaks and repair if ness.
did the water pump get changed when the head was swapped,these leak but are hard to spot as they can leak from the telltale hole at the 6 oclock position, this leak goes undetected behind the crank pulley.

New water pump being fitted Tuesday and head re fitted and sealed with wellseal, fingers crossed this works now

[BongoDaz]

All fixed, i would like to thank everyone who was kind enough to reply to my problem and the good advise they gave, if anyone is changing the head on there Bongo, or skimming and replacingn the Gasket, please take note of some of the replies i got in the earlier threads, to some up i got my Bongo fixed by replacing a New water pump ( a must ) a new rad, New Head, and made sure the gasket was fitted with wellseal, also i replaced the main water pipes, as to the original reason for the cracked head, i will never know, but the finger strongly points to the water pump, and for the low cost of these on the likes of E Bay, its a must change when fixing Head Gasket problems, i hope this is going to be some help to anyone with the same problems

[mikeonb4c]

All fixed, i would like to thank everyone who was kind enough to reply to my problem and the good advise they gave, if anyone is changing the head on there Bongo, or skimming and replacingn the Gasket, please take note of some of the replies i got in the earlier threads, to some up i got my Bongo fixed by replacing a New water pump ( a must ) a new rad, New Head, and made sure the gasket was fitted with wellseal, also i replaced the main water pipes, as to the original reason for the cracked head, i will never know, but the finger strongly points to the water pump, and for the low cost of these on the likes of E Bay, its a must change when fixing Head Gasket problems, i hope this is going to be some help to anyone with the same problems

Really useful feedback. The key with Bongos seems to be fixing the underlying problem that led to the head/gasket going or, better still, spotting the problem in its early stages. A low coolant alarm takes car of leak alerts, and maybe we should be fitting engine block temp gauges to warn when engine running abnormally hot. I have a TM2 but have yet to get around to fitting it.

[mikexgough]

Japanese owners are known to change water pumps at coolant change times.... just saying..

[BongoDaz]

All fixed, i would like to thank everyone who was kind enough to reply to my problem and the good advise they gave, if anyone is changing the head on there Bongo, or skimming and replacingn the Gasket, please take note of some of the replies i got in the earlier threads, to some up i got my Bongo fixed by replacing a New water pump ( a must ) a new rad, New Head, and made sure the gasket was fitted with wellseal, also i replaced the main water pipes, as to the original reason for the cracked head, i will never know, but the finger strongly points to the water pump, and for the low cost of these on the likes of E Bay, its a must change when fixing Head Gasket problems, i hope this is going to be some help to anyone with the same problems

Really useful feedback. The key with Bongos seems to be fixing the underlying problem that led to the head/gasket going or, better still, spotting the problem in its early stages. A low coolant alarm takes car of leak alerts, and maybe we should be fitting engine block temp gauges to warn when engine running abnormally hot. I have a TM2 but have yet to get around to fitting it.

Yeah i agree, im thinking of having the Alarm fitted as well

[Simon Jones]

Japanese owners are known to change water pumps at coolant change times.... just saying..

That would be every two years on average which seems a bit unnessary. A decent quality part should easily give 10 years of service. My everyday car is a Volvo XC70 which is shortly due for second cambelt change at 190,000 miles & the consensus from the forums & owners club is that it should not be replaced as a matter of course as the genuine parts are extremely reliable and will last for another 200,000+ miles.

On the other hand, the other half's Golf GTI needed a new pump after just 47,000 miles as the plastic impeller dropped of shaft due to poor design. So much for VW reliability & German engineering .