QPV 4.7S: variators rattle - even after cam caps modification?

petrD

New Member
Messages
4
Hi To All, another newbie on this forum - Am the happy owner of Mas QPV 4.7S for about half a year (MY2008, now 75k km on the clock). Shortly after I purchased the car (70k km at that time), the engine started to rattle - typical sound of variators...It got worse, even when the outside temperature went higher (rattling 8 out of 10 starts). The engine suffered misfires (barely noticeable, but seen on diag tool) and that strange "slapping" noise (going away when open the oil filling cap). So we decided to do a variator job.

When dismantling cam caps, we noticed that those were probably already modified. Also the check valves are not sitting at the same height, and are not staked (pics attached).

I just wanted to ask the forum couple of questions:
  • is that cam caps modification done (properly)?
  • could the "sagging" check valve block the oil flow, causing the lack of oil for variator?
  • would the chain tensioners be a main cause of rattle similar to variator rattle, or just a contributor? (when we "pressed" the timing chain, the tensioners were pretty "soft"...)

Thanks a lot for any help or advice.

Peter
 

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petrD

New Member
Messages
4
Hi Michael, am based in Czech Republic. Unfortunately the support is not so great...I visited official dealer for prepurchase inspection and later fix. New knock sensors were needed (bloody rodent visited the engine bay) - engine cut the rpm at 6.5k, not revving to red line, they even did not find it without my intervention...andthey had no clue about the cam caps mod's..and other stuff.
 
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Michael

Member
Messages
340
I'd take some good photos and send to Maserati UK. A few emails and you'll find the head of customer service. Sorry don't have a name but I've used them in the past and they are helpful
 

MaseratiGent

Member
Messages
162
I have a wet sump 4.2L. My rattle was quite bad in an unmodified engine. I had the repair done (and parts sent off to Maserati). The rattle was entirely eliminated for about 50 startups and has now re-appeared as if nothing had been done. Reading this: https://www.maseratilife.com/threads/engine-rattling-noise-at-start.96161/ was instructive.

I'm now debating buying a 4.7L without rattle and getting it fixed preemptively or getting a 3.8L QP6. I love my QP5 it's better than the QP6...

Read that article and you'll see there's no getting away from the fundamental problem.
 

Phil H

Member
Messages
4,107
I have a wet sump 4.2L. My rattle was quite bad in an unmodified engine. I had the repair done (and parts sent off to Maserati). The rattle was entirely eliminated for about 50 startups and has now re-appeared as if nothing had been done. Reading this: https://www.maseratilife.com/threads/engine-rattling-noise-at-start.96161/ was instructive.

I'm now debating buying a 4.7L without rattle and getting it fixed preemptively or getting a 3.8L QP6. I love my QP5 it's better than the QP6...

Read that article and you'll see there's no getting away from the fundamental problem.
That's a pretty informative thread, and post #13 (the last one) seems very logical and could explain a lot.

PH
 

ChrisQP09

Member
Messages
2,994
That's a pretty informative thread, and post #13 (the last one) seems very logical and could explain a lot.

PH

Great read! Interested angle on the transmission, I drive my post variator engine MC in sport/manual where i can! Good for the soul apparently
 

philw696

Member
Messages
25,113
Totally agree what a great write up and explanation.
When I worked for Maserati we were just told to change them as if it was an upsell.
Most people had warranties and for them the cost was covered.
It was all for earning a good bonus for us techs hence why I don't want to be working for dealers anymore.
 

Oneball

Member
Messages
11,069
In my mind there’s some major flaws in that guy’s opinion (post 13 on ML) the biggest being that oil pressure is lower at 2000rpm than it is over 2800rpm.
 

stevepen

Member
Messages
139
So I’ve just had my variators replaced, cam caps modified and new solenoids. But reading that article they could wear out and start rattling again unless the revs are kept high. Have I read that right?


Sent from my iPhone using Tapatalk
 

Gazcw

Member
Messages
7,696
My variators are done but I have noticed if I put her away very hot and leave for a week or so then the next start up I get a brief rattle. If parked following normal driving temps. No rattle. I put it down to hot and slightly thinner oil leaving the scene maybe. Not too concerned tbh as it is so brief!
 

Gazcw

Member
Messages
7,696
So I’ve just had my variators replaced, cam caps modified and new solenoids. But reading that article they could wear out and start rattling again unless the revs are kept high. Have I read that right?


Sent from my iPhone using Tapatalk
Drive it and dont worry not worth it. Too much scaremongering on variators sometimes I think. Yes if you are buying make sure they are done but if they are not leave it still the rattling is really bad. Well I would anyway.
On the brightside at least you haven't got to replace the clutch very often!
 

CatmanV2

Member
Messages
48,539
In my mind there’s some major flaws in that guy’s opinion (post 13 on ML) the biggest being that oil pressure is lower at 2000rpm than it is over 2800rpm.

Jason at Enzo's gave up picking holes in the logic. The place is great at reverse engineering theories.

C
 

eight

Junior Member
Messages
94
I would be staggered if Ferrari had designed a valve train incapable of operating at, say, 1200 rpm with hot oil. Stick some 10/60 in it?
 

Motorsport3

Member
Messages
868
I thought leaving the car idling for too long is generally not advisable due to possible oil starvation at certain parts of the engine.

How long do you wait before driving off from cold?
 

philw696

Member
Messages
25,113
Always used Shell as that was the choice of Maserati /Ferrari
Start her up and 5 bar on the pressure gauge off you go.