V6 Noisy Engine & Oily Plug

[mikeWalsall]

Ummm ... looking at .. the .. camshaft ...

There are four of them .. plus 24 hydraulic valve lifers .. any which could give top end noises ..!!

[zoomzoomluke]

Ummm ... looking at .. the .. camshaft ...

There are four of them .. plus 24 hydraulic valve lifers .. any which could give top end noises ..!!

Well you know what I mean!

So what could be up with the HLAs? Doesn't sound like the normal sticking I used to hear on my MX6. The pitch is totally different.

But anyway, I will find out soon enough. Garage has warned me that getting a diagnosis is going to run up hundreds of pounds

[mikeWalsall]

IF ... it is due to noisy hydraulic self adjusting tappets / lifters .. sometimes an engine flush .. and a re fill with fully synthetic oil .. may .. quieten them..

[Simon Jones]

I'd be cautious of using any engine flush additives. Used some in Wynns flush mine and there was a slight increase in tappet noise afterwards

With regard to lack of power, there isn't really anything different that happens at 1/4 tank but running with low fuel continually will increase chances of problems with the fuel pump as it used the petrol to keep it cooled and it will run hotter as the tank gets emptier.

A blocked tank breather system may cause problems if air cannot fill the space vacated by the fuel. You could try leaving the filler cap slightly loose to see if it makes a difference.

[zoomzoomluke]

So the garage couldn't find anything top end causing the noise. Power wise everything seems ok, and there is no oil/fuel/water mixing issues. The garage thinks it could be a cracked piston but really not sure without doing considerably more diagnostics at a cost of several hundred quid.

With regard to lack of power, there isn't really anything different that happens at 1/4 tank but running with low fuel continually will increase chances of problems with the fuel pump as it used the petrol to keep it cooled and it will run hotter as the tank gets emptier.

A blocked tank breather system may cause problems if air cannot fill the space vacated by the fuel. You could try leaving the filler cap slightly loose to see if it makes a difference.

I tried that before taking to the garage, no effect.

When it's dropping power it's pulsing every 1.5 seconds between normal running and no power, so i'm guess the fuel pump is on the way out?

[mikeWalsall]

I note you do not have LPG fitted yet so dunno if it's relevant or not ..

My V6 always started and ran OK while on petrol .. but in cold weather and in traffic it was always 'lumpy' when initially switching over to LPG .. that .. perump ................ perump ............ perump ... sound of losing .. picking up revs .. it got to to the point, if not touching the accelerator .. the engine stalled ..

Fitting new plugs .. leads .. dizzy cap and rotor .. 100% cured the problem..

[zoomzoomluke]

I note you do not have LPG fitted yet so dunno if it's relevant or not ..

Nope, no LPG yet. Have saved up just about enough to get the conversion then this happens

I think is definitely a fuel supply issue as it only happens below quarter of a tank of fuel, and gets worse the less fuel there is below that. I am changing the fuel filter tomorrow but alas I don't think it really matters if the engine turns out to be knackered.


Don't know if it helps diagnosis but I am only getting the engine noise when accelerating and not while holding a constant RPM.

[Simon Jones]

I can lend you a fuel pump if you want to try it before committing to buying a replacement? If you can cover P&P cost, you are welcome to borrow for as long as you need it.

You can send sample of engine oil away for analysis which may shed some light on what is going on inside (a bit like a blood test). To be honest, if it were me, I'd get a good used engine from George at BongoSpares and sell the old one for parts to recoup some of the cost (baggsie first dibs on the distributor ).

[zoomzoomluke]

Been a while since looking at this. Bongo has been at at the yard for months now and just brought I back as was about to give up.

Simon, if I could borrow the fuel pump that would be terrific. I presume the electric pump is submersed in the tank and therefore being cooled by the fuel? If so, it would make sense that below 1/4 tank it's cutting out.

Now the engine noise issue is really stressing me out. I have tested just about everything I can and pulling plugs etc does not change the noise in any way which (i think / hope) rules out rod bearings and i'm pretty sure it's not rod knock or big end. What I did think though would possibly be the torque converter? Only starts to knock at high RPM . I'll have to take the box off and have a look.

Well at least the oil leak has been sorted

[Simon Jones]

Hi, drop me a PM with your address. I'll have to locate the pump over the next few days as I've stuck it somewhere safe and will need to power it up to check its ok. Not sure if it's possible to detach it easily from the sender unit so I'll probably include the whole lot.

[SparkyB]

Hi,
did you ever get to the bottom of this issue?

I have a '97 V6 which is rattling/rumble when cold.
It was also running very rough when cold until I bought new plugs and leads. On inspection a couple of the plugs were not tight, so I wonder if that was the real issue.

Hasn't fixed the rumbling noise though, and so I have bought an MX6 engine as a base to rebuild it.
Should be fun .......

[Simon Jones]

Are you sure it's compatible? Don't similar vintage MX6's have the KL series engine rather than the J5? Sounds like an interesting project though .

[Northern Bongolow]

is it possible that something is floating about loose on the crank shaft side of things, im thinking front pulley or drive to it etc.

http://lushprojects.com/bongopartsmk2/c ... mgno=.html.

ive attempted to see if these engines have balance shafts but cannot see any, simon has some good pics of the engine somewhere. .