Could Sheared Exhaust Manifold Bolt/s lead to overheating?

[bandario]

Greetings all you cool cats and fine felines,


After almost a year of extremely proud and trouble free bongo ownership I have finally started down the path we all seem to follow at some point with these vehicles. 1995 TD 4x4.


Recently started getting 'the whine' when I take off quickly, turned out it was not the wife after all.

Inspection confirms sheared exhaust manifold bolts and it must be pretty severe because exhaust gas is venting around the engine at idle.

Also have a minor leak of some kind from the inlet manifold my mechanic said at last inspection and the little green 'valve' has snapped off of the pipe behind the AFM and I have no idea what it does.


We have got no history of overheating with our bongo + I have a TM2 fitted with sensor at rear of engine block and alarm set @ 110 celcius.


After recently moving house we were heading up a very very long, extremely steep hill and the alarm started going off so we pulled over. Personally I am not sure this was the right thing to do @ 110C...obviously she was getting hot but I think it was the act of actually stopping the car at this temp which pushed her over the edge and the coolant came bubbling out of the overflow and she reached upwards of 117 after pulling over...there was however a significant amount of hill to go so I guess it could easily have happened anyway or been worse.


Right, one professional flush and bleed later + my own bleed for peace of mind and we were away again. (Manifold leak/ sheared bolt has not been fixed at this point...we need some more $$)

Since that incident the car has been back to normal in daily use. We have done massive drives and temps are back to normal between 85-95 most of the time.

The problem is where we live now, there are a LOT of hills, we are surrounded by mountains and going over one is often the only way to get where we are going. Every single time we try to head up any of these the bongo temps shoot up again and I am left trembling in fear. This ONLY ever happens on the hills.

Car also feels like it is lacking a fair bit of power.

Just wondering what you guys think, is it possible that the exhaust leak is somehow related to the overheating on hills? I can understand the lack of power.

Also, any ideas what this green nipple might be coming off the inlet manifold just before the AFM?

It seems like it is in the right place to cause some problems.

Here, have a look at my nipple:



Would appreciate any thoughts.
If we crack a head, combined with the manifold issues I think I would be pretty tempted to just replace with a brand new mazda bravo engine and be done with it.
Hooroo

[Northern Bongolow]

http://www.igmaynard.co.uk/bongo/forum/ ... ifold+stud.
that may help.

the little green thing is a one way valve, it can be repaired, it vents the vac from the egr exhaust gas recirc to the inlet manifold i think.
on the subect of the egr. with this still conected you are putting exhaust gasses into the inlet manifold to be reburned, this is adding to your heat, blank it off and it will give you more power as it will be burning fresh air not second hand air(if your emisions are ok for your yearly test etc.)

the manifold stud or studs breaking could contribute to overheating if the fans arnt coming on or cannot cope with the engine bay temps under the covers. if climbing slowly for a time the airflow will be limited. it will also knacker your alternator too as this will get hot as its very near.

sounds like your stat is getting lazy, or your front rad could do with replacing/flushing.
other things to check are the fan switch on the rear of the head above the starter motor, this brings on the fans at 1st slow then both, then fast, if this is not right you may be missing out on good cooling.
change the gearbox oil and clean the filter as it relys on the front rad to cool the gearbox oil.

i would recomend fitting a gen mazda thermostat also, there is good evidence to sugest they are far better made than most of the copy parts available over here and do the job loger. also check on the different boiling points of coolant that you may find available over there, every little helps

[jaylee]

Ady beat me to it.. It is to do with the egr...?!!

part 13-995 valve check http://lushprojects.com/bongopartsmk2/c ... f02.html#4

[bandario]

Thank you for the replies.

I have ordered a mazda stat and will have that replaced at the same time as studs in the next couple of weeks.

I'll make sure to drop in and keep you guys updated.

Also pretty keen to see if this mechanical mob feel confident in blocking off / removing all the EGR gear.

We don't get any regular emissions testing here.