broken rocker arm

[chinwaa]

Hi,

My diesel bongo appears to have a broken rocker arm. It broke down outside a local garage that I've not used much before so I thought i'd give them a go. They're currently researching the job and putting a quote together. Meanwhile, please does anyone have any tips about the following:

1. how much I might expect to pay
2. does the cylinder head have to come off
3. presumably it's best to replace all rocker arms
4. anything else worth doing while it's in bits
5. any gotchas to look out for?

They just replaced the timing belt 3 days before it started running like a bag of spanners. My understanding is that this is just an unfortunate co-incidence, as a timing problem would have resulted in bent valves and piston damage etc. Is that correct please? Thanks very much folks.

Cheers,
Matt

[g8dhe]

Not unheard of by any means see this thread http://www.igmaynard.co.uk/bongo/forum/ ... 89#p454289 which suggests it may not only be the rocker arm but the cam shaft as well ??

[Bob]

Really bad luck.

Which engine do you have?

[rita]

Really bad luck.

Which engine do you have?

This might help

My diesel bongo appears to have a broken rocker arm.

[Northern Bongolow]

as in the thread above check to see if the cam shaft has broken. check under the bearing caps, they break there, or take the top off and wind the engine over and check everything is moving.

there have been several rockers reported breaking over the years but this is usually shortly after a head change and the adjustment has gone out or someones fit a head described as built up and ready to go etc, and not checked the rockers for setting gap.

my first thoughts would be that someone has broken into the cooling system when they did the timing belt, this could let air into the system, this can lead to a warped head that can snap the cam shaft as it raises in the center, bit of a leap i know but they dont usually go for no reason. have you checked the coolant level ?.
how well was it running after the timing belt swap, was it ok. if the belt was fitted slightly out i suppose its possible to run but run hotter and warp the head.

not suggesting any of the above happened here but maybe suggesting it may trigger something in your head that helps you figure out whats happened.

[teenmal]

as in the thread above check to see if the cam shaft has broken. check under the bearing caps, they break there, or take the top off and wind the engine over and check everything is moving.

there have been several rockers reported breaking over the years but this is usually shortly after a head change and the adjustment has gone out or someones fit a head described as built up and ready to go etc, and not checked the rockers for setting gap.

my first thoughts would be that someone has broken into the cooling system when they did the timing belt, this could let air into the system, this can lead to a warped head that can snap the cam shaft as it raises in the center, bit of a leap i know but they dont usually go for no reason. have you checked the coolant level ?.
how well was it running after the timing belt swap, was it ok. if the belt was fitted slightly out i suppose its possible to run but run hotter and warp the head.



not suggesting any of the above happened here but maybe suggesting it may trigger something in your head that helps you figure out whats happened.

This might give you a clue.....


They just replaced the timing belt 3 days before it started running like a bag of spanners..

[Northern Bongolow]

thats 3 days after the belt though, what was it like just after the belt. it reads like it may have been good then bang.

[chinwaa]

Hi, thanks for all your replies.

I'll be sure to ask them to check the camshaft for breakage too. When you say "...or take the top off and wind the engine over", does that mean just the rocker cover or something more (like the cylinder head) - I'm just about at the limit of my engine knowledge here

Haven't had a head change, but I did originally take it in for a tiny coolant leak, still waiting for a hose. The alarm was whimpering occasionally, so I would immediately stop and top it right up again. Fairly confident that the coolant level didn't drop below critical, but maybe air could have got sucked in through the leaky coolant pipe, causing it to run a bit too hot?

I thought the engine was running a bit noisier right after the timing belt change but it settled down when it warmed up. Then 3 - 4 days later it developed into something a lot more serious - horrendous noise, no power, no speed, vibrations etc. Thanks for your thoughts, this is beginning to feel expensive....

[Northern Bongolow]

just take the rocker cover off.
it did sound like there was more to this than the thing just snapping, i think of myself a bit like a doctor, ask the right questions and the answers usually come out. just kidding, before you all jump down my kneck. .

if the cam isnt busted i would move forward by getting them to do a compression test on each cylinder, this may show up any valve, head, gasket damage.

[Bob]

Really bad luck.

Which engine do you have?

This might help

My diesel bongo appears to have a broken rocker arm.

Thanks, missed that under my nose.

[mikeonb4c]

Hmmm. Interesting researching links between cambelt change and rocker arm breaking:

http://www.rac.co.uk/forum/showthread.p ... iming-belt

http://www.honestjohn.co.uk/forum/post/ ... tm?t=79931

Are just two I picked up on. To me, there does seem to be a possibility the cambelt change and rocker arm breakages are linked. Can the 'new' garage identify if the timing is as it should be before tinkering with the cambelt. And does a new set of rockers need to be fitted, to be safe? And how might the cambelt changing garage react to a suggestion they didn't set the engine timing correctly (are they experienced with Bongos?).

[cmm303]

Good research Mike. I'm sure everyone was thinking it.

[chinwaa]

Thanks for the info about the camshaft check and compression test.

I did query the possibility of a timing problem just after the belt change, when it was a bit clattery, before it went really wrong, but he assured me he was very careful and marked it all up properly etc. He has had a Bongo of his own in the past. I think I'll go for a full set of rockers to be safe.

Following the very useful diagnostic detour (I learnt a lot), can anyone perhaps help a bit with the original questions

1. how much I might expect to pay for a new camshaft (maybe), new rockers and labour
2. does the cylinder head have to come off - I guess 'no'
3. presumably it's best to replace all rocker arms - I guess 'yes'
4. anything else worth doing while it's in bits
5. any gotchas to look out for?

Thanks for any further info anyone might have.

[teenmal]

chinwaa,you need to get your vehicle to an Experienced Mechanic/Engineer. They may want to remove the head for a full Inspection, they may also want to replace with a complete head Assy.

Re the cost involved you need to ask for an Estimate for all alternatives and only go with the one with a guarantee.

[chinwaa]

Thanks all, I'll let you know how it pans out.