1991 400 SE Which Oil + Tickover

[beduch]

I have been using Millers 5/40 full synthetic oil with no problems but I have heard from various sources that the Rover V8 engine prefers a good quality standard multigrade oil, any comments.
Also the tickover on my car is sometimes erratic and it also runs very rich at tickover, I have checked and changed most of the usual parts (this seems a general problem with hotwire cars according to other owners I have talked to, any suggestions.
Apart from this the car runs and drives very well

[350matt]

Wotcha
Depending on the condition of your engine then you might be OK with 5/40 but I'd prefer to run at least a 5/50 or even 15/50 as this is what the engine originally ran on. As to the engine preferring a multigrade, then I suspect this is for the reasons I just stated, but if you can find a 'thick' synthetic oil (eg. Mobil 1 Racing spec 5W/50) it'll definitly be a better oil. As for your erratic idle speed check the condition of all the hoses after the airflow meter as it may be pulling in air somewhere. Also check the wiring on you idle speed control motor and finally you may want to contact Mark Adams (contact in Sprint/ tower view) as he's the most knowledgable person around for these injection systems.

[Brm Brm]

Not familiar with "hotwire" cars but assuming you have a stepper motor, erratic idle or "hunting" is a classic "stepper motor" problem.

[Stig]

The best oil for Rover V8's IMHO is Valvoline Racing. Not that widely available though so try your local motor factors.

[REV-EREND]

If you are running synthetic - stick with it. Funny things happen to oil seals when you switch back !

Re - erratic tickover - pull out the stepper motor
from the back of the plenium chamber and check :
1. the large nut inside is tight
2. it is seated properly

Rev.

[jvaughan]

Have been running my 400SE on Magnatec 15/40 for the last 5 years no problems.
My argument about not using the more expensive synthetics is that 10years plus ago they didnt have the advances in synthetics as they do today, so I stick to a good quality mineral based one.

Have always discouraged any dealers from putting mobil1 in the wedge too.

I buy bulk oil from France once a year (and usually pay £9-10 for 5 litres, that does me for 12 months).
Paul hudson from Oxford buys Mobil-1 in bulk for his 1995 Chimera..

Plus mine is a hotwore model for whatever good that does

>> Edited by jvaughan on Thursday 28th February 14:00

[andymadmak]

Richard Thorpe at Wedge Automotive reckons that the wedges should be run on top quality mineral oil, not synthetic. Reckons synthetics are too thin.
Andy 400se

[jvaughan]

also they make less of a dent in the wallet )

[stig]

Valvoline Racing IS a mineral oil

[beduch]

Thanks for the replies to my queries just to confirm that I have changed the stepper motor, in factI have 2
stepper motors(they are the same as those fitted to the old MG Maestro EFi + MG Montego EFI + Rover 216 EFI) and I checked for air leaks etc. The problem only happens now and then.
As for oil I used Mobil 1 before I tried Millers and found that with Mobil the car used a great deal more oil