ENGINE NOISE...

[matbor]

I'm not sure if i'm hearing things, but my v8 is making a noise, like a constant tapping noise, this only happens while it is warming up (about 5 mins then disappears, well nearly completely !!)

I have just change the oil about 3,000 kms ago (did most of those km's in the last week !!!) Use Penrite HPR15, engine has done 128,000km's now.

any ideas ??

[defute]

Hey Matbor,

it sounds as though you have noisy hydralic lifters.

If the oil you are using is too thin - causing the lifters to bleed down while the engine is switched off, the lifters are worn or the engine's oil pressure is low - it can take longer than normal to fill the lifters full of oil on start up. This will cause a tapping / knocking noise. This noise will normally be isolated to the top half of the engine.

It may pay to check the engine's oil pressure and possibly try running a slightly thicker oil.

[matbor]

thanks, how would i find out the enigne's oil pressure ?

[bigbugga]

I had this same problem and was told the same this from my LR dealer.
$x amount of dollars to fix, was a big number too


But
He then turned about and for $10 ran a cleaning agent through the oil for me.
After 4 days no more tapping on start up, and that was 8 months ago.

[matbor]

do you know what sort of cleaning agent they put though the engine ?

Has anyone done this before ? What do u have to do to flush the engine ?

I have read a little up on this, but not what products are available in australia ! Also any suggestion's on what oil i should put in after this ? Have been using Penrite HPR15 (every 5000kms, new oil and fliter) with no problems until now. Should i put that in again to see if the flushing agent fixes the problem or change to a different brand oil !!

I have also read somewhere that changing to a thinner oil will help fix the problem, because more than likely the oil passages are blocked up and if you run a thinner oil though the system the degrent in the thinner oil will help break down the blockage. Is this true ?

Sorry for so many questions.

matt.

[matbor]

has anyone got any ideas ?

Thanks

[Defender200Tdi]

I've read a bit about this on other forums (fora?) in the past. It was suggested that rather than using a flushing agent, you could try a normal diesel engine oil for a few thousand km's. The diesel oils are very high in detergents & dispersants which will achieve much the same thing as a cleaning agent, but be a bit more gentle and take more time. My only concern with flushing agents (or even diesel oil) would be if your engine was badly worn and the cleaning removed carbon deposits from your rings which were keeping the compression up, but at only 128,000km I wouldn't have thought that your engine would have that sort of problem.


Paul [img]style_emoticons/<#EMO_DIR#>/biggrin.gif[/img]

[Defender200Tdi]

I just had another thought on this. I seem to recall that the 3.9 V8's went through a stage where they were developing excessive end float in the cam shaft. This produced a knocking noise that was a bit deeper and slower than the tappet rattle. I think Landrover developed a fix for it in the mid 90's. I'm sure Defute would know more about it. You there Marcel???



Paul [img]style_emoticons/<#EMO_DIR#>/biggrin.gif[/img]

[LandyAndy]

Hi
Wyyns "Tune Up" works a treat on the same problem in sticky lifters in Falcon 6 X flow motors.
I have the same problem at the moment in my 202 powered Ser3,that has developed since the weather has cooled down.Im running penrite HPR50 and suspect its too thick till warmup.I bought diesel oil to do an oil change last weekend for the exact reason in the last post.Perhaps your HPR15 is a little too thin,maybe use the "Tune Up" for 500ks or so then the Diesel oil??????????
My 202 only runs LPG and the oil is as clean as the day it went in so I dont think carbon is a problem for me.
Does your oil blacken up quickly? If so diesel oil may increase your oil consumption,this may not be that bad as you are using a very light grade,going up to HPR20 or 30 would cure that.I had a falcon that was using up to 4 lts of GTX a week,changing over to HPR50 droped it to 4lts a month and I got another 18 months out of the motor till I re-built it.
Andrew

[defute]

Hey Matbor / Paul,

sorry for the delay guys - I'm working on the Press Launch of the new Jaguar XJ6 into our market in Melbourne - we've just finished preparing the vehicles for tommorow's round of journos!!

The knocking noise that Defender200Tdi has mentioned effected 3.9lt V8s and was caused when the camshaft moved backwards and forwards in the cylinder block due to excessive end float.

Camshaft end float can be measured by either removing the inlet manifold or front timing cover and checking the cams extremes of movement with a dial guage.

From memory (and I stress 'memory' - and I can confirm this when I get back to the office) there were 3 possible fixes that could be employed depended on the amount of end float that the camshaft had and the vehicle's engine# -

1. fitting a 'button' to the nose of the camshaft and machining (filing) it to the appropriate / calculated thickness to bring back within spec 'camshaft end float'. Fitment of the 'button' reduced cam end float by allowing the button to butt against the inside of the engine's front timing cover as the cam moved within the cylinder block. This contact was not audible due to the type of material that the button was constructed from and did not cause any damage to the timing cover. This is the cheapest fix!!

2. fitting a 'camshaft retaining plate' which was bolted to the front of the cylinder block and machining it to the appropriate / calculated thickness to bring back within spec 'camshaft end float'. The fitment of the retaining plate is not much more expensive than the 'button' fix but requires more effort to machine to size due to it's design!!

3. fitting a new camshaft, lifters and camshaft retaining plate. This is by far the most expensive fix and still requires the retaining plate to be machined to the correct thickness!!

I hope this answers your questions!!