V6 Noisy Engine & Oily Plug

[zoomzoomluke]

Hi Guys,

I've not been on here for quite a while. My bongo has been sitting unused for a year or so due to family matters that have prevented us from going away this / last year. Been regularly turning her over and taking her out for a little run so generally should be OK. MOT a couple of weeks back flew through.

I have been meaning to service her for a couple of months but an unexpected long trip to Cornwall yesterday meant that she had to have a long run without service.

Long story short I was in the middle lane of the M5 when I had an almost total loss of power. Heart sank and the owner of any bongo always fears the worst.

Managed to limp off the M5 and into the services and looked around to see what could be amiss.

Checking all the plugs I found there was a large amount of oil on top of one of the plugs. I clean it up, topped up the oil and got home without any further issues. I checked the plug several times on the way back and nothing much in there, nowhere near the swimming pool of oil that I found the first time I looked.

I am thinking this is just a failed rocker cover gasket but any other possibly scenarios would be appreciated.

Now this could be a coincidence but for the last couple of weeks there has been a knocking at certain RPM, I thought It was just an external part but it seems more and more like it's something "inside". Any thoughts on what it might be? I am planning an LPG conversion in a few weeks but am now worried the engine's not going to be up to the task. Its got 160,000KM on the clock.

Here is a little video I produced today. Not sure how well the noise comes through though.

http://youtu.be/LSJlSLGHarY

[haydn callow]

First thing I would do is remove each plug lead one at a time and give them a really good examination and clean.....remove and replace all plugs....then go from there.

[zoomzoomluke]

Each other lead is fine, all clean and dry. Going to change the plugs themselves this afternoon once I can be sure no oil will drip down when I take the mucky one out.

[mikeWalsall]

Some years back I bought a cheap Vauxhall Ecotec with exactley the same symptons .. it was oil seeping past the rubber cam cover gasket and filling the spark plug tubes ..

... the noise was ' sticking'hydraulic tappet(s) .. I fitted a new gasket .. used some engine flush .. and re filled with fully synthetic oil ..

As the Mazda cam cover is alloy and not plastic as on the Vauxhall ... you may be able to 'nip up' the cam cover nuts ..

[Simon Jones]

If you get a misfire on one of HT leads you'd still have 5 working cylinders so I'd not expect 'total loss of power' so there may be something else going on in addition to the oil leak.

If you change the cam cover gasket (which does sound like its leaking) also change the cam cover nut seals (about £12 for 10 from the US) as the rubber will have set hard and most likely will distintigrate when removed. I've just replaced some of mine that were leaking and the rubber was well and truly knackered.

[zoomzoomluke]

If you get a misfire on one of HT leads you'd still have 5 working cylinders so I'd not expect 'total loss of power' so there may be something else going on in addition to the oil leak.

If you change the cam cover gasket (which does sound like its leaking) also change the cam cover nut seals (about £12 for 10 from the US) as the rubber will have set hard and most likely will distintigrate when removed. I've just replaced some of mine that were leaking and the rubber was well and truly knackered.

so i've now changed the plugs. the old plugs were very worn. there was nothing to cause alarm on the spark side of the plug.
i have nipped up the bolts a little and left cylinder 5 with it's lead off and can't see any oil running down into the tube. i'll see how it goes but in the mean time will order a set of cover nut seals and both gaskets.

i'm hoping nothing else is going on but like i said, cleaning up the oil solved the power loss issue completely.

just wish i could work out whats causing the knocking at 2500 RPM and above... any ideas anyone?

[rita]

Personally I don't like the sound of your engine, I would be very concerned about the knocking sound.

This could be caused by various malfunctions/wear etc, you need to have the source of the noise confirmed and the oil pressure etc checked.

There is a possibility that it has a HLA malfunction or a camshaft failure (for starters).

Good Luck.

[Northern Bongolow]

is it still knocking now the plugs are fresh and the oil leaks stopped.

[zoomzoomluke]

is it still knocking now the plugs are fresh and the oil leaks stopped.

yep afraid so

sound like it's top end, just hoping it's a tensioner or something. pretty sure it's unrelated to the oil leak unless of course a prolonged misfire could have caused something else to fail?

[flossie]

Hi ive not been on here for AGES!!! Hope everyone is keeping well!!

My V6 Bongo is poorly sick at the moment ... just as Dad and I are about to head to Scotland (i confess we are picking up our motorhome on the way but thats another story) .. anyway given that i am partially deaf i struggle with engine noises. Dad has mentioned a rattling ... so took it in to Discount Trucks last week and Fred as usual gave it the full Platinum service attention ... he couldnt hear the rattle and it didnt seem to be there while idling he said it sounded more like a bit of a roar ... so he isolated various parts (having changed oil to high grade synthetic and new filter) and narrowed the roar down to tensioner and/or alternator which we discussed the implications etc of these going wrong and decided to tackle the issue after my holiday.

However Dad did a tip run for me today and has basically said he is not prepared to go to Scotland in it with the issue - he described it as rattling when it decelerates. The reason ive tacked this on to the current post (and i hope its not hijacking!) is perhaps its a similar issue? So anyway Bongo going in tomorrow again and they will change both the tensioner and then if needed the alternator ... will report back. In the meantime i thought id peruse the Oracle of the forum and came across this thread so thought id tie the bits together; they are convinced its 'top' of the engine rather than the internals (if that means anything to you guys lol!)

[flossie]

Looking like new engine needed - gutted does not come close and where do I start

[helen&tony]

Hi
Have a word with George at Bongospares2012 on e-Bay...he's sorted quite a few good spares for the Bongo clan, and he will freight engines!
Cheers
Helen

[mikeonb4c]

Looking like new engine needed - gutted does not come close and where do I start

Jeebers that's bad news. How was that conclusion arrived at and what could possibly have caused it to happen? Really sorry to hear your news though there's lots of happy transplant owners. Good luck getting it sorted.

P.s. PM David Edwards to ask how his happy transplant experience went.

[New Forest Terrier]

You have been unlucky with that Bongo Liz. It has had so many problems over your ownership. If Fred says the engine is knackered then it is knackered. Its really decision time, is the rest of the Bongo worth the cost of a new engine. V6 engines have been the same since the start and I am sure one can be sourced easily. George should be able to come up with the goods.

What caused the failure? Yours has had all the proper attention, cam seals and timing belt changed. You mentioned picking up a motorhome. Will that be the Bongo replacement?

[zoomzoomluke]

So just a quick update.

The total power loss was nothing to do with the misfire, guess it was just a coincidence. I discovered this by the fact that the power loss only occurred when the fuel reached about a quarter of a tank, it never cut out above this level. So as previously thought,

The bongo is now in the garage having the camshaft looked at as their stethoscope indicated that it was a top end noise.