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Engine Noise

Posted: 27 Mar 2017 14:01
by Clem
Since I bought my 4.8 Patrol new in 2013 I have used it most days. It now has 37k km on it. Last week I parked it and it has been standing for a week. This morning I start it. There's one hell of a loud "klak, klak, klak" from the engine bay as the engine starts and quite a lot of vibration. Carries on for a few seconds and then largely disappears, though I can still hear some unusual noises for a minute or two. I drive to work and all is normal.

Now I assume that in all probability this had something to do with oil pressure and hydraulic lifters but can anyone shed anymore light on matters? I've had cars with noisy starts but nothing ever like this

Re: Engine Noise

Posted: 27 Mar 2017 14:52
by Tinus lotz
Are you sure its not the starter motor turning with engine??

Re: Engine Noise

Posted: 27 Mar 2017 15:43
by Wilkie
You did not smell fuel or see black smoke out the exhaust..??

Re: Engine Noise

Posted: 27 Mar 2017 15:50
by Kagiso II
NO OIL
NO or LOW water
Engine mounting loose or broken
Crank carrier bearing
Klink vir my na droog -- gooi nuwe olie. Nuwe water met anti freeze
Kyk na die WATERPOMP ook


Die muise wat ingetrek het in daai 2 weke skraap hul meubels bymekaar :lol: :lol:

Re: Engine Noise

Posted: 27 Mar 2017 17:28
by Clem
I switched the car off and on again a couple of times after the noise had gone away. Nothing. Completely normal. The nature of the vibration is the kind of thing you would get if an engine wasn't firing on one cylinder. The noise was the kind of thing you might get when a piston strikes a valve. I wonder if a valve wasn't stuck open. Oh well. I'll check the basics and then we'll go from there. I'm only going to worry about it if it happens again. With only 37K on it, I'll have the argument with Nissan if necessary.

Re: Engine Noise

Posted: 28 Mar 2017 06:13
by Michael
This is one of those "not easy to find" noises. If it happens every single time you start its one thing, but by the sound of it, it was is a once off thing?

Re: Engine Noise

Posted: 28 Mar 2017 08:35
by ricster
I may be off by a mile here, but my guess would be that due to the Patrol standing for a long time, the oil drains back into the sump leaving the top of the head "dry". I don't know what the ambient temperature was when you started the Patrol, but I assume it was a bit chilly or at least a bit cooler than it has been in the last few weeks/month or so.

With the oil all the way back to the oil pump or worse back all the way to the pump, when started, the thick oil now needs to travel back up and around the little channels all over the block and head, and into those hydraulic lifters. I think this takes a second or 2 till the oil flow system is full flowing.

Although it isn't good for an engine to experience these types of noises as there is already a huge wear factor every time we start up any engine, I doubt this would have caused any significant problems.

It would be interesting to know what oil they used when they serviced your Patrol last. I am no oil expert, but I wonder if a 5 or 10w 40 grade oil would be better to prevent this than a 20w 40 grade oil specifically for the "cold" starting times.

Re: Engine Noise

Posted: 28 Mar 2017 09:08
by Clem
Cedric, I think that's exactly it. Oil levels are normal by the way. Not sure what oil Nissan used. I had a similar problem with a Land Rover once - ticking when first started. A 5W40 (which flows easily when cold) solved the problem. As Graham will be taking over servicing, I will talk to him about the oil spec.

All is still normal today.

Re: Engine Noise

Posted: 28 Mar 2017 13:20
by Peter Connan
I had a somewhat similar problem with mine at one stage. It had a bad timing chain rattle upon first start in the morning.

I think in my case it was due to sludge build-up in the timing tensioner. I started using a thinner oil, and it stopped after a week or so.

Re: Engine Noise

Posted: 28 Mar 2017 17:07
by Clem
Thank you Peter. This does not sound like a timing chain rattle but rather more like a "knock" – by which I do not mean a bearing knock but simply a knocking noise. I think it probably has something to do with the hydraulic aspects of the valve train. But I do not really know…