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Ticking noise and burning oil

iMacThere4iAm

iMacThere4iAm

Tom Long
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750
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Morecambe
I had a bit of a rough trip home yesterday - spent too much time and money in the supermarket in Boulogne then caned it to Calais just in time to miss my ferry.
When I set off from Dover I noticed a 'ticking' noise from the engine when under load, as if one cylinder was pinking. Also the oil was below the minimum mark and the engine was overheating. (on that note, my oil and temperature warning lights only work when decelerating hard - I must fix that.)

Not knowing what was wrong and afraid to do major damage to the engine, I refilled the oil and set off gently along the A-roads, keeping the engine torque as low as possible to avoid making the ticking noise. I must have averaged around 40mph and arrived home at 3:30AM.

So please, help me with a differential diagnosis for a ticking engine under load and rapid oil burn.

My first theory is a piston ring failure - I'm going to borrow a compression tester and check this as soon as I can.
 
[QUOTE My first theory is a piston ring failure - I'm going to borrow a compression tester and check this as soon as I can.[/QUOTE]

I think that this is a theory worth investigating as this is the most probable scenario.

If you are lucky - very lucky, you may have just have affected the rocker arm clearances - so all you will need to do is adjust them.

May luck be on your side!

David
 
Or perhaps a burnt out valve, if it is I shall stick my Tongue out at you as I did offer you some lead replacement. Good luck getting it sorted out, I hope it doesn't turn out too expensive!!
 
Fingers crossed its not too major :(

All else fails spare engines are usually available !

Regards,
Andrew
 
I did a compression test today. Pressures for each cylinder are, from 1 to 4:
13.5 bar
12.7 bar
11.7 bar
12.5 bar

Is that a reasonable range? I can't seem to find a reference in the manual.

Along the way, I noticed that all the plugs except no.2 are horribly fouled up with an oily deposit.
It is probably just a coincidence, but plug no.2 is an NGK, while the others are BERU. This shouldn't make any difference, I just thought I'd mention it.

I've bought a mechanic's stethoscope – a very cool gadget, but I need an assistant to load the engine while I listen for the click. Hopefully I'll get to do that this weekend.

So what's it look like? The oil in multiple cylinders points me towards a gasket failure, since I don't imagine three piston rings would fail simultaneously like that.
 
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Your NGK is a BP5HS... I have 4 NGK BP7HS on my r4, on advice of the shop guy. NGK site gives for our engines BP6HS.
Quite funny.
 
They are very high readings. I don't relate to Bars so I converted to psi by multiplying by 14.5. How did you take these readings?

As a general rule, the readings need to be within 10% of each other. Your readings indicate that you need to pull the head off and overhaul - this is apart from anything else you may find wrong.
 
Random thoughts

Piston rings as you say

Worn valve guides due to lack of oil to the top ?

Leaky rocker cover gasket - are the plugs getting covered in oil from the outside ?

Random guess: Failed head gasket causing oil to enter cylinders and not get to the top as it should - hence the ticking as well?
(think your thinking this)

- Also clean the plugs and put them in a different order - that should eliminate the make / model of the plugs

I guess the compression test could be misleading if half the cylinders have oil in them increasing compression!
 
The BP5HS is too hot-especially for a GTL. That's maybe the reason for it being so clean. Are the rest of the plugs of the correct grade for the engine? Plug reading can be very misleading if they are not suitable for the engine!
 
Champion list the correct plug for the GTL as L92YC and I used these in my GTL for 70,000 miles without any problems. The NGK equivalent is BP5HS.
 
Compressions don't look that bad. I'd not bother rebuilding the engine on their account. Well worth checking tappet clearances though after a long high speed trip with no additive.

I'd try some BP6HS plugs - those are what I've always used. If one plus was running much hotter than the rest then you might well have been getting pinking in one cylinder.

The oil warning light only works under deceleration because it's a too late light. It tells you you have zero oil pressure. On deceleration if the oil is much too low it will slosh away from the oil pickup in the pump and you'll have zero oil pressure. This is a bad thing - don't rely on the light to tell you when to check the engine.

I put about 0.75L of oil in my car over the trip. Sounds like yours used about 1.5L. Not ridiculous consumption.
 
Thanks Malcolm, that's a little bit reassuring. I guess in the excitement of Thenay I forgot I was driving almost 2000 miles! I just hope I didn't badly overheat or wear the engine.
I shall have a look at the tappet clearances next.


I've been using a BP5HS plug because as Steve says, it's listed as the equivalent to L92YC. I do have a complete set of BP5HS somewhere, but only put one in because I'd cracked one of the otherwise fine BERUs. Nevertheless, I'll get a set of BP6HS and experiment.
 
Steve Hennessey said:
Champion list the correct plug for the GTL as L92YC and I used these in my GTL for 70,000 miles without any problems. The NGK equivalent is BP5HS.
Click to expand...

I am not an expert, I am just trusting what the ngk site told me when I asked him the right plug for my engine:
http://www.ngkpartfinder.co.uk/car_commercial_extra.php?id=8002

The last year I changed all 4 plugs and the seller gave me 4 BP7HS. And I think he checked on a book...
So three different thoughts...

I have to say too that now, after 10-15k km done, the plugs seems to be a little dirty and crust-covered... But I do not know what does it mean.
 
So... Today I tried decoking the engine with some expensive spray called 10K Boost. It produced the expected result (lots of thick white smoke) but didn't stop the noise.
Another compression test gave numbers that are no better than the first time:

1 13.1bar 190psi
2 12.8bar 185psi
3 13.8bar 200psi
4 12.1bar 175psi

It did reveal a brand new crack in my exhaust – see the photo below. Not a new worry, since I knew I'd have to replace the entire exhaust very soon anyway. It's literally falling to pieces.

Anyway I have ordered a set of Champion LF92YC plugs since we know those are correct - it says so right on the engine!

I think my next step is to check the valve clearances. I understand that means lifting the rocker cover. Is there anything I should know about this job? Presumably I will need a new gasket, although the existing seal looks suspiciously like silicone mastic.

I suspect my inlet manifold gasket might have failed too, because I noticed a sizzling sound and some steam after spraying the cleaning stuff into the carb, as if it was oozing out somewhere between the inlet and exhaust manifolds. I'll be investigating this more tomorrow - is it the one where you spray WD40 around and look for the smoke in the exhaust?
 
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Hi Tom, when checking valve clearences, the "rule of nine" is useful. No 1 valve fully open check No 8, No 2 fully open, check No 7 etc. When you fit the new gasket, clean the mating faces thoroughly and apply a smear of grease to both faces. It stops the gasket sticking, so making removal next time easy, and helps to make an oil-tight seal. Regards Brian.
 
alewis said:
As the rocker cover is quite easy to get off you might as well try cleaning up the old gasket and reusing it. If all else fails you can get a complete set from ebay for not too much !

http://www.ebay.co.uk/itm/RENAULT-4..._CarParts_SM&hash=item20badd9ede#ht_671wt_934
Click to expand...

I suspect the old gasket will be no good so I've ordered a new one.
Although the description of that set says it fits the 1108cc, the photo is clearly of an 845cc gasket set. Got to be careful on ebay!
 
I reset the valve clearances although they weren't bad. I broke and then fixed my accelerator cable. I reset my timing (with a useless neon timing light that only works in pitch darkness). I retuned my carburettor with a Colortune (mixture screw all the way in, apparently). Compression test still reports somewhat higher than normal. I've fitted a set of genuine Champion L92YC plugs. I've checked that my vacuum advance works correctly.

I've tried everything I can think of and the noise has not gone away. Today I'm giving up and seeking professional help.
 
What about the crack on the exhaust pipe? Did you fix it? It may well be the cause of the noise. The same gos for a leaking exhaust manifold gasket.
 
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