Page 1 of 3

No Compression it seems

Posted: Fri Jun 18, 2010 12:42 pm
by TimW
HI All,

I'm after a little advice please.
My wife was just taking the kids to school this morining when she had gone about 30 meters the van an awful loud mechanical bag of spanners noise. She stopped the engine and called the RAC.

The RAC man said there was not a lot he could do but it seemed as though there is a total loss of compression.
The engine turns over now, not noisily but very fast, as you may expect with potentialy no compression.

No signs of coolant loss, and no oil leaks either (No Really, no oil leaks :) )

My questions is, does this sound like the timing belt has slipped? (the belt is still there attached)
What else could have caused this failure?

Many Thanks

Tim

Now living in Kent.

Re: No Compression it seems

Posted: Fri Jun 18, 2010 2:18 pm
by 321Away
If you can see the timing belt is in place, its onlay a simple matter of lining up the marks, in general a belt being 1 tooth out either way, the car will still run but there will be a change in power characteristics?
Julian

Re: No Compression it seems

Posted: Fri Jun 18, 2010 4:04 pm
by gmaczbongo
Sounds like the timing belt has gone.
It may still be there but have no teeth on it.
Banging noise could be valves to head noise.
Fast turning over is because the starter is not turning over the engine anymore.
Either the camshaft or the crankshaft is no longer turning or both.
This is only a guess from your description.

Re: No Compression it seems

Posted: Fri Jun 18, 2010 4:19 pm
by TimW
Thanks for the replys, I'm going home now and will take a peek..

Re: No Compression it seems

Posted: Sat Jun 19, 2010 1:07 pm
by TimW
Hi,

Ok, had a look this morning.

I undone the timing belt cover so I could get a peak in at the belt, whilst the belt was intact there was lots of rubber debri behind the cover. When I checked the tension wheel i could turn it easily against the belt, is this normal?

Next question, the local garage lent me a manual on timing belts, so i can see in the book its a matter of lining the marks up on the top and bottom pulley and then adjusting the belt tensioner. But in the real world how hard is it to do on my bongo? the access from the top seems very restricted.

(How much is a belt?)

Thanks

Tim

Re: No Compression it seems

Posted: Sat Jun 19, 2010 1:17 pm
by phoenixroxy
try turning the crank pully by hand, or turn the engine over and watch what is happening. sounds like the belt is slipping over the camshaft pulley or the camshaft is snapped im afraid.

Re: No Compression it seems

Posted: Sat Jun 19, 2010 1:27 pm
by TimW
I turned the engine over on the starter and there are no untoward noises other than obvious lack of compression.
So I'm leaning toward the cam belt has slipped and put the timiming marks out.

But the real question is how hard is this to change at home? The process seems easy enough but the actual access to the front of the engine seems impossible.


Has anyone done the job themselves at home?

Thanks

T

Re: No Compression it seems

Posted: Sat Jun 19, 2010 1:41 pm
by phoenixroxy
depends on how confident you feel. there is a cutout on the front face of the camshaft pully this goes to the 12 oclock position there are also marks on the crankshaft pulley and fuel pump. sure there are diagrams on here somewhere.

i just replaced my timing belt with the help of mirrors and a light to help see the marks, as you say access is very difficult. i changed the belt while replacing the cylinder head so had inlet manifold and hoses off which improves access a lot.

i will be surprised if thats your only problem though i would remove the centre console and rocker cover to check the camshaft first

Re: No Compression it seems

Posted: Fri Jul 09, 2010 12:11 pm
by TimW
Hi All,

Finally got around to my Bongo, I had to take a day of work.

I thought I'd just wip the cam belt off first and to my dismay it was mostly fine :(
With that in mind I wipped the rocker cover off expecting the worse, I wasn't disapointed.

Cam shaft snapped clean in two behind the first lobe!

Ok, so im off to order a new shaft, anything else that needs to be taken into consideration?

Thanks

T

Re: No Compression it seems

Posted: Fri Jul 09, 2010 1:14 pm
by roofraisers

Re: No Compression it seems

Posted: Fri Jul 09, 2010 2:08 pm
by gmaczbongo
Camshafts snapping in any vehicle is rare.
Usual cause is a belt problem that allows free movement of the camshaft in relation to the crankshaft.
Valves hit piston and usually the valves bend.
Tough valves and engine continuing to turn means something must give way.
The cam shaft snapped in this instance, usually it is the belt or the valves or the engine stops dead.
If it was mine, the head would come of to have a look at the valves.
I would expect a dent in at least one of the pistons and a bent valve.
It could also be just a weak camshaft. Investigation needed as too cause of problem.

Re: No Compression it seems

Posted: Fri Jul 09, 2010 2:24 pm
by mikeonb4c
gmaczbongo wrote:Camshafts snapping in any vehicle is rare.
Usual cause is a belt problem that allows free movement of the camshaft in relation to the crankshaft.
Valves hit piston and usually the valves bend.
Tough valves and engine continuing to turn means something must give way.
The cam shaft snapped in this instance, usually it is the belt or the valves or the engine stops dead.
If it was mine, the head would come of to have a look at the valves.
I would expect a dent in at least one of the pistons and a bent valve.
It could also be just a weak camshaft. Investigation needed as too cause of problem.
v. sound advice I fear. You could get a 2nd opinion from a (Bongo) garage. Incidentally, just to be safe, do we assume this is a diesel?

Re: No Compression it seems

Posted: Fri Jul 09, 2010 2:31 pm
by TimW
yup its a diesel, Im rather hoping I'm as lucky as the other fella was (Monkey).

Either way I cant take it to a garage as I'm out of funds, so I'm going to buy a Camshaft from Ebay.
I looked at the followers and they seem fine, I'll get the shaft first and go from there.

Thanks so far for the advice.

T

Re: No Compression it seems

Posted: Fri Jul 09, 2010 2:38 pm
by maxheadroom
This may help a bit;

http://www.igmaynard.co.uk/bongo/forum/ ... m&start=45

but just ask if you need more help.

PM sent

Re: No Compression it seems

Posted: Fri Jul 09, 2010 2:44 pm
by maxheadroom
PS change the cam belt and the tensioner and spring too