Hello Folks,
Wondered if anyone had experience of using a fully synthetic oil (recommended) with Molyslip for the V8?
Have used Molyslip on other models with good results and i'm trying to keep my 4.0l V8 quiet as i had a problem with one of my VVT's "clacking" from start up which disappeared when hot. Any advice appreciated.. Charlie.
Fully Synthetic oil with Molyslip for V8
Re: Fully Synthetic oil with Molyslip for V8
Just casting my mind back to my 4 litre 8 S-type which had the same engine as the X308.
I took to using fully synthetic in place of the recommended semi-synthetic as specified by Jaguar. A naturally aspirated 4 litre doesn`t really need the extra protection afforded by a fully synthetic oil as the oil doesn`t get the pounding or higher temperature aspect as the N/A motor doesn`t receive the punishment metred out by a supercharger.... Hence R versions being specified as needing fully synthetic to cope with higher internal stresses and higher engine temps. However, fully synthetic oil is less resistant to burning in service and I always found the synthetic oil stayer cleaner for longer in my 4 litre N/A V8.
Additives are often a matter which can cause controversy. Many contain PTFE particles which can block oil ways and cause oil starvation. That issue has raised its head many times over the years with some products. Advice would tend to suggest that staying away from PTFE type additives might be good advice. You might check to see what Molyslip contains.
The VVT units on these cars do get noisy particularly when cold and with accumulated mileage. A certain amount of gear wear is known to occur and my S-type V8 at 96k miles was just starting to develop the issue when I sold the car. I tried the well known additives commonly available but never saw any improvement. I`ll add that I also worked as a consultant for EDT for a while, marketing the excellent EDT engine decontamination system to garages. We were particularly interested in whether the process could help quieten noisy VVT units but reluctantly had to conclude that even our system could not quieten VVT units that had developed wear. Worn, means worn and that means replacement of the units to quieten things down a bit.
In my opinion adding off the shelf additives is really like flogging a dead horse. Additives tend to contain detergents which can displace a build up of gunk but in its displacement running clearances increase and even more noise develops. Remember, oil cannot build up a worn component. My personal opinion is that you shouldn`t get overly optimistic that friction reducing additives will fully or partly cure this particular issue.
Mike K
I took to using fully synthetic in place of the recommended semi-synthetic as specified by Jaguar. A naturally aspirated 4 litre doesn`t really need the extra protection afforded by a fully synthetic oil as the oil doesn`t get the pounding or higher temperature aspect as the N/A motor doesn`t receive the punishment metred out by a supercharger.... Hence R versions being specified as needing fully synthetic to cope with higher internal stresses and higher engine temps. However, fully synthetic oil is less resistant to burning in service and I always found the synthetic oil stayer cleaner for longer in my 4 litre N/A V8.
Additives are often a matter which can cause controversy. Many contain PTFE particles which can block oil ways and cause oil starvation. That issue has raised its head many times over the years with some products. Advice would tend to suggest that staying away from PTFE type additives might be good advice. You might check to see what Molyslip contains.
The VVT units on these cars do get noisy particularly when cold and with accumulated mileage. A certain amount of gear wear is known to occur and my S-type V8 at 96k miles was just starting to develop the issue when I sold the car. I tried the well known additives commonly available but never saw any improvement. I`ll add that I also worked as a consultant for EDT for a while, marketing the excellent EDT engine decontamination system to garages. We were particularly interested in whether the process could help quieten noisy VVT units but reluctantly had to conclude that even our system could not quieten VVT units that had developed wear. Worn, means worn and that means replacement of the units to quieten things down a bit.
In my opinion adding off the shelf additives is really like flogging a dead horse. Additives tend to contain detergents which can displace a build up of gunk but in its displacement running clearances increase and even more noise develops. Remember, oil cannot build up a worn component. My personal opinion is that you shouldn`t get overly optimistic that friction reducing additives will fully or partly cure this particular issue.
Mike K
X350 Co-ordinator
2004 XJR
2004 XJR
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xjscharlie
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- Joined:Mon Mar 18, 2013 6:30 pm
Re: Fully Synthetic oil with Molyslip for V8
Many thanx for the reply which makes sense. I have little confidence that adding Molyslip will reduce the noise.
It is certainly the case that worn components and increased clearances can result in noise which can increase with temp. I had a V12 a long while ago with a bottom end rattle which i cured with STP or at least it took the noise away.
On this V8 i've managed to cure the VVT rattle on both banks but it has returned on the RB after about 6 weeks.
So one can assume its due to wear in the RB VVT which i may have to replace BUT if its worn why does it go quiet when it heats up & then noisy again when it cools? Nobody knows..Rgds.
It is certainly the case that worn components and increased clearances can result in noise which can increase with temp. I had a V12 a long while ago with a bottom end rattle which i cured with STP or at least it took the noise away.
On this V8 i've managed to cure the VVT rattle on both banks but it has returned on the RB after about 6 weeks.
So one can assume its due to wear in the RB VVT which i may have to replace BUT if its worn why does it go quiet when it heats up & then noisy again when it cools? Nobody knows..Rgds.
Re: Fully Synthetic oil with Molyslip for V8
I believe it has to do with wear in the gear drive and is also oil pressure related. Take a look at one of the online manuals for the car and see how the VVT units function.
Mike
Mike
X350 Co-ordinator
2004 XJR
2004 XJR
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