Top end rattle at start up

[Panicracing]

I've read much about top end rattle at start up on the 4200 over the years with horror stories about variator replacement, accumulator etc etc. Even speaking to main dealers and indys it was a common issue and a bit of follower noise at start up for a second or to was fine. Over the years of owning my GS I've always had a 1 or 2 seconds top end rattle at start up. Nothing apart from annoying. When I done the cam cover gaskets a year ago I replaced the 2 non return valves at the front under the cam shaft caps covers which made no difference. After a bit of research and investigation with the oil gallery's I noticed there was another non return valve in the LH cylinder head about 6 inches from the back which I assume supplies the variator and accumulator and then linked to the RH bank. I removed this and compared to the new replacement the spring was quite weak. Fiited the new valve and job done no rattle at start up. Tested it over last week leaving for a few days and starts rattle free every time.

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[Gp79]

That's interesting do you have any photos or a part number for the valve?

I replaced the oil accumulator this year and it did make an improvement, such as no rattle when re-start after re-fueling - so 5-10minutes.
But then i still get a rattle after it has been stood for an hour or so.

I would like to get this fixed as i think it is very noticeable, but probably my ears are tuned into it now!

Regards Greg

 

[Zep]

This is very interesting to me too. Do you mean item 14 in this diagram?

Zep

 

[Contigo]

My understanding is that the GS and later 4200's are less likely to suffer from variator issues because of this non return valve being fitted. It's the wet sump engines which don't have it and when left for longer periods the oil drains away and the rest is history. The cam caps mod is effectively to put a non return valve in place.

 

[CatmanV2]

Yeah, the 4200s certainly can rattle at start. Mine did. It was no big deal, but could sound somewhat disturbing. If that valve fixes it, this must be a good thing?

C

 

[Zep]

My understanding is that the GS and later 4200's are less likely to suffer from variator issues because of this non return valve being fitted. It's the wet sump engines which don't have it and when left for longer periods the oil drains away and the rest is history. The cam caps mod is effectively to put a non return valve in place.

I'm not sure - this valve doesn't fit in the bearing caps for the variators from what Panic is saying, it is a third valve only on the LH head.

I think there is a check valve on the variators on the wet sump engines from the factory (there is one listed) but I imagine the new valve wasn't as good as the old one and so they change it back when doing the mod.

Still, I'm going to doing anything I can to keep oil in the top of my engine

 

[CatmanV2]

It's still not clear (to me at least) what the 'fix' for the variator issues actually is. I cant see any difference in the parts between the early and later models, and if it was just an upgraded part, one would think a straight upgrade would sort it.

C

 

[Panicracing]

To confirm part number for valve is 180267 and new washer 10261060. About £20 for both from Dick Lovett here in Swindon. Like I said before I replaced the 2 check valves under the front cam caps 18 months ago but made no difference at all. This one has cured the split second rattle 100%. I was led to believe that the front valves supply each variator but unsure. I was told by a tech but he was not 100% that the back valve supplies the variators and is linked to the rh bank via the accumulator hoses. Would be good to get confirmation from somebody in the know.

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[Panicracing]

I was led to believe that the later 4200 engines wet sump blue cam covers had the from valves removed from the front cam caps and they had an issue with top end rattle. These were then retrofitted as a fix by Maserati but needed machining. From what I can see the 4200 dry sump red cam cover has never changed.

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[Panicracing]

That's interesting do you have any photos or a part number for the valve?

I replaced the oil accumulator this year and it did make an improvement, such as no rattle when re-start after re-fueling - so 5-10minutes.
But then i still get a rattle after it has been stood for an hour or so.

I would like to get this fixed as i think it is very noticeable, but probably my ears are tuned into it now!

Regards Greg

I was looking into this and even got all gaskets here ready to remove the inlet manifold and carry out an inspection but after speaking to a tech at Dick Lovett he had never seen one fail. For £20 and 1/2 hour the valve is worth ago.

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[Zep]

To confirm part number for valve is 180267 and new washer 10261060. About £20 for both from Dick Lovett here in Swindon. Like I said before I replaced the 2 check valves under the front cam caps 18 months ago but made no difference at all. This one has cured the split second rattle 100%. I was led to believe that the front valves supply each variator but unsure. I was told by a tech but he was not 100% that the back valve supplies the variators and is linked to the rh bank via the accumulator hoses. Would be good to get confirmation from somebody in the know.

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Brilliant, thanks for the info. I assume the cam cover has to come off?

 

[Panicracing]

The rear valve is in the V on the LH cylinder head. Just remove the centre plastic trim for access. 17mm socket and a rag to soak up any oil whilst removing. Will send a picture if you want. Car is at my unit so will be tomorrow.

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[Zep]

Brilliant, thanks for the info. I assume the cam cover has to come off?

Scratch that, is it this bolt head?

 

[Panicracing]

Scratch that, is it this bolt head?

that's the one.

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[Zep]

that's the one.

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Cracking - thanks

 

[BL330]

Big thankyou for posting this. It could be the solution to my problem too.
Sometimes during warm up a rattle in the left bank will develop, but only sometimes.
What does happen all the time though is a rattle in the left bank after I've given the car a good workout.
Then the rattle settles down and goes away until the next flogging.

 

[Gp79]

All good info thank you.

From what I understand this valve will / might only stop a variator rattle at start up before oil pressure is up.

If you have a tick / rattle when the engine is running (normal oil pressure) this could be due to worn tappets, cam(s) or a variator problem etc etc.

 

[BL330]

All good info thank you.

From what I understand this valve will / might only stop a variator rattle at start up before oil pressure is up.

If you have a tick / rattle when the engine is running (normal oil pressure) this could be due to worn tappets, cam(s) or a variator problem etc etc.

I had a Maserati & Ferrari credentialed mechanic briefly look at it and he showed by the application of revs ( probably 2,000 to 3,000 ) oil could refill at the top of the motor making the tick go away. This gave me confidence it wasn't tappets or cams. He did speak about restricting the flow of oil back down the motor and the valve pointed out in this post with stronger spring rate encourages me the fix may be straight forward.

 

[Gp79]

Might be worth replacing the variator oil filters, they live below the cam caps on each bank, the new filters came with the rocker cover gasket kit from superperformance.

I replaced mine but found the old ones clean so it made no difference.

 

[Zep]

I'm going to go for this one first as it looks like a 30 minute job, which is lucky as it is my attention span...