after ex. manifold work, no lo-revs power and white smoke...

[tomwharf]

hiya bongo oracles,

so, the story goes like this...

had some work to the exhaust manifold done as we had the squeaks (like a fanbelt). it was the stud at the rear of the engine that had gone. had this work done by a non-bongo specialist garage. after about ten minuted driving around after picking it up 5 litres of coolant dropped out of the system (aagghh!). i am quite sure it didn't overheat, thank goodness the wife noticed a "grinding" noise and pulled over (though this noise may be a red herring) and noticed the coolant leak. the AA filled it up with water and we drove home (1mile) and back to the garage in the morning (1/2mile). The AA tested for CO2 in the coolant system and found none (CO2=headgasket or cylynderhead damage). could have been MUCH worse.

... 2nd visit to the garage, they took care to properly replace the coolant at their expence (how kind?!) and i think its okay. However, we now have a new problem. a slightly intermittent but REALLY serious loss of power at under 2000rpm and then, when it gets going, quite a lot of whiteish smoke, which smells like unburnt fuel. once over 3000rpm and travelling at 30mph it has some spriteleynessback, but at low speeds and revs, COMPLETELY gutless, so much so it is almost undrivable.

our mechanic (I am looking for a replacement) suggested that it could be a build up of inlet manifold sludge.

Does this sound right?
Could these symptoms be caused by be anything else?

I think I have a few options;
1/ italian tune up i.e. bang down the motorway at 80+ for an hour or two, and hope it clears it
2/ take off the inlet manifiold and clean it out (or replace, they are only 20 odd quid)
3/ disable Exhaust Gas Recirculation and stop the sludge getting in (see http://www.igmaynard.co.uk/bongo/Forum/ ... f=3&t=6479)

is there any other things i might check?

Any advice greatfully recieved

Cheers,
Tom

[Driver+Passengers]

I think the symptom of a gunged up inlet manifold is usually black smoke (rich mix due to insufficient air being sucked in). A quick read of the emissions factsheet in the members area suggests that white smoke could have a number of causes including incorrect injection timing and/or coolant in the combustion chambers (the latter may be an indication of a blown head gasket).

Can your garage describe to you what they did w.r.t coolant first time round (ie the process which they followed in order to bleed the system if they drained and refilled?) You should also seek specifics of what they did on your second visit.

I don't know how any of this would relate to power loss or 'grinding'. Not saying it wouldn't, just that I don't know.

Don't take option 1, options 2 and 3 are worthwhile - good discussions here viewtopic.php?f=3&t=52285, but you want to sort out your coolant issues first. Put your location in your profile and someone local may be able to assist, or recommend a local specialist.

Good luck - you might be safest to not drive it until you can bottom this out.

Edit: PS. Warm welcome!

[Simon Jones]

Where did the 5 litres of coolant escape from? What has been done to address that leak? The lack of oomph sounds like a problem with the turbo and / or associated pipe work. Check the big black U shaped pipe a the front of the turbo to ensure it's refitted correctly. Assuming it was all ok prior to having the stud replaced, check all around the manifold and turbo to see if anything looks amiss. There's also a pipe from inlet manifold to the diesel pump which can affect performance if it becomes disconnected.

[jaylee]

I hope I've identified the right bit.. Also check the pipe coming up from the inter-cooler hasn't come adrift from the intake at the front of the engine..? Part 13-230 http://lushprojects.com/bongopartsmk2/c ... no=.html#4

[Northern Bongolow]

if you check the pipework simon and jaylee point out and its all ok, check the crankcase/rocker breather that goes to the rear of the head into the air inlet pipe to the turbo, then i would go for a compression test, particularly pots 2-3.
sounds like its popped the head. this usually occurs at no2 or no 3 pot exhaust valves or more precisely the valve seats.
as its 2 exhaust valves and 1 inlet valve it cracks between the 2 exhaust ports, this can be very difficult to see/find/test as it cracks internally. when they crack like this they usually pass the sniff test as it blows the coolant out of the exhaust,not gasses into the coolant hense the sometimes seen white smoke.
you could try removing the exhaust manifold again and looking for water marks out of the head.
you could also check the camshaft as they have been known to break into several pieces under the pedestal bearings (they look ok until you turn the cam then you see that all of the cam isnt turning), this is caused by the head overheating and lifting slightly and trapping parts of the cam.when checking the cam, check the valves are all within the correct settings, a tight valve could indicate a damaged valve head/seat.

[haydn callow]

Apart from everything else it sounds as though the garage didn't know how to bleed the cooling system.....ask them how they did it and did they know there is a "bleed" pipe under the passenger seat.....If they didn't do it right then there are problems ahead.....
you can download the info from this site and see the youtube vid's (bleeding bongos)
It is super important to get this right,
Perhaps the garage overheated it after doing the work whilst testing

[tomwharf]

Wow,

thats a lot of reply's. Thanks all. here are some aswers to your questions

1 - the coolant loss seemed to have come from the overflow pipe on the coolant header tank under the bonnet, as there appeared to be coolant all over the battery tray.

2 - compression test? would this tell me if it had cracked the head?

3 - If it has a cracked head due to dropped coolant that is the garages fault, what are the chances of them admitting liability and covering cost of the work?

I live in Hackney, E9 6EN. any tips for a local bongo specialist?

....bugger.

[haydn callow]

O.K. that defo sounds as though the garage did not bleed it as it should have been done.....DO NOT DRIVE IT ANYWHERE......download the bleeding instructions (or contact me for a copy) get the garage to recover the Bongo....get them to bleed it according to the instructions and if poss watch the Vid's.......providing they do it properly it should be o.k. but if it spews up again I'm afraid it is a new head required and this is down to the garage not knowing how to bleed it.......This happens so often......every garage "thinks" they know how to bleed every vehicle.....Bongos are differant due to the mid engine and all the extra pipework...

[teenmal]

Hi tomwharf,

You need to get to the root of the problem first.Why did the vehicle blow 5 litres of coolant from the header tank.
Did the garage drain the coolant to change a manifold stud?


Cheers.

[tomwharf]

just had a word with my garage and they have said they will try and diagnose the issue.

Major question is - will just one overheat crack the cylynder head?

teenmal I have no idea why the broke into the coolant system, but they didn't replace the coolant, but they must have let some air get into it which blew the coolant out when it heated up.

Thanks,
tom

[haydn callow]

Yes...one overheat could very easily crack the head.........also pressure tests and "sniff" tests can often be inconclusive.....If it does turn out to be a major job I would get the garage to allow you to get it to a bongo garage and see how much they will help out with costs.....if they haven't done a Bongo rebuild before you could be in exactly the same position again in 3 months time....but way out of pocket.....Can you get it to Discount Trucks...Newbury

[dandywarhol]

Thinking outside the box a bit - especially the grinding noise - the turbo is liquid cooled from the cooling system and coolant could escape internally into the exhaust system, giving white smoke and a coolant loss AND a noise if the turbo bearings are goosed. "Search" might bring up previous problems along these lines.

[Simon Jones]

Good point. If the garage removed the manifold, they would almost certainly have also disconnected the turbo and this is probably where they would have broken into the coolant system which could have resulted in air entering the system, pressure building up, etc etc.

[progroup]

if you check the pipework simon and jaylee point out and its all ok, check the crankcase/rocker breather that goes to the rear of the head into the air inlet pipe to the turbo, then i would go for a compression test, particularly pots 2-3.
sounds like its popped the head. this usually occurs at no2 or no 3 pot exhaust valves or more precisely the valve seats.
as its 2 exhaust valves and 1 inlet valve it cracks between the 2 exhaust ports, this can be very difficult to see/find/test as it cracks internally. when they crack like this they usually pass the sniff test as it blows the coolant out of the exhaust,not gasses into the coolant hense the sometimes seen white smoke.
you could try removing the exhaust manifold again and looking for water marks out of the head.
you could also check the camshaft as they have been known to break into several pieces under the pedestal bearings (they look ok until you turn the cam then you see that all of the cam isnt turning), this is caused by the head overheating and lifting slightly and trapping parts of the cam.when checking the cam, check the valves are all within the correct settings, a tight valve could indicate a damaged valve head/seat.

That would be 2x INTAKE Valves and 1x EXHAUST Valves

From my recent experience I can say ditto to Haydn's reply plus to do the job properly, you should also be aware of the condition of all hoses, clamps, steel pipes, condition of rad, fans, and more importantly a combustion chamber leak test. You may have already 'cracked' the head usually #2, or #3 cylinder valve seats or inside the valve stem. If near valve stem, CANNOT 'stitch' the head - must replace the entire head casting. If it still runs and you see white smoke, how much coolant is being consumed if you find no visual leak?

Cheers, Dave

[tomwharf]

so...

it seems that there is a consesus gathering on this thread around the "doomsday scenario" of a cracked cylinder head. I am not entirely convinced as the van was not running for more than 15minutes post coolant loss, but will take the advice seriously. I will be taking the van to the garage on tuesday morning for them to diagnose and correct all the damage they have caused.

i imagine the easiest option once whatever the damage is has been diagnosis to accept the garage to do the work. they are not idiots, and I am getting the work done by the boss, not the lackey. thay have admitted the mistake regarding the coolant leak, and therefore any further work resulting from this. though no experts on bongos, they have two regulars with bongos, and I suppose this is their learning curve (AAAGGGHHH!!!) (deep breath)

-Are there any factsheets/advice etc on the replacement of the cylynder head I can give them?
-Where can i get a new cylinder head - genuine mazda preferred?
-How can I, with no access to any tools beyond a adjustable spanner and an enquiring mind verify that their is/ or is not cracks on the head prior to giving it back to them?

all of your help is well recieved, cheers all!

Thanks,
Tom