Engine runs rough on cold star

Hi guys I have an lr322 2002 and recently had timing chains done,when I start the car it is really rough with the belts squealing also for around 2 mins then it runs perfect. I have had the garage strip the front casing and check the timing and cleaned and reset both vanos but still have the same problem.The engine has been flushed about 5 times as well has anyone have any idea what this problem is.

The belts squealing will the main auxiliary belt at the front I would think either not tensioned properly which if a garage did it then it’s quite straight forward to get it right using the tensioner or it could be the power steering pump on the near side lower front of the engine out of alignment as that can be adjusted when fitting. The aircon runs off a separate tensioned belt at the lower front offside of the engine.
Does the squealing sound like the belt?
if you can do it without chopping off a hand you can spray water using a plant sprayer onto the belt to see if it stops , I would start with the power steering pump.
On cold start there is a secondary air injection pump that pumps air into the inlet for a few minutes to reduce emissions but mine has been removed was never fitted, do you have a thin silver pipe running across the front of the engine?
Did they replace the vanos seals when they did the work?

Thanks for your reply,the belt/belts have been adjusted but they only squeal when the car is running rough,when the car runs as it should the noise goes away,the belts do not squeal when starting the car when it’s hot.However I do have a thin silver pipe across the front of the engine if this is removed would it make a difference? The vano seals seemed ok when removed and have been check twice but I know where your coming from regarding oil pressure to the cams.I “think “ I know a fair bit about cars but this has me beat and can’t solve it.if you can elaborate on this thin pipe on the front of the engine it would be much appreciated or anything else that would help . Thanks Alistair.

Hi, I'm not sure if the SAI would make much difference but I was wondering if you had it fitted but didn't have it connected correctly after the rebuild if it would cause cold start problems.

When i first did my vanos rebuild, when i started the car it ran really rough and i had not tensioned the aux belt correctly, after i tensioned it correctly and after a few starts it ran really smooth on idle, i am not sure how the aux belt could give poor engine idle so the two may not be connected.

I wondered if by changing the vanos seals it makes the vanos really stiff to move and if that affected the timing until it warmed up as the vanos does take a while to bed in, did they actually fit new vanos seals ?

the other thing i would check is how well the throttle body is fitted and also if there are any other vacuum leaks.

Can you plug it in to any diagnostics

+1 water spray to track down belt or pulley squeak, but do be careful.

How many miles have you done since the work, as maybe set to be okay after 'run in'?

Another thing is the engine adaptations if the garage reset them which will take a little while for the engine ECU to re learn.
I would try plugging it into good LR diagnostics to check for faults that can be cleared.

I'd say Diag is a good shout..

Aux belt could be pulley misalignment.

If it's Vanos related the motor will run like shyte pretty much all the time, and in most instances a fiddly Vanos can be heard rather easily

Will also lack punch, the M62 is a rather lively unit

I think the aux belt could be a good shout I will get that checked tomorrow,I have only done 30 miles or so since the last strip down so might wait for a few more days to see if it clears itself.I had it on the diagnostic machine after the first strip down and it did say the timing was out but it was checked on the second strip down and it was spot on.I will carefully spray some water on the belts also to check what belt is noisy thanks for your advice it’s always handy to try and solve this issue and I will let you know if and when I solve this.

You could get it warmed up and clear codes and then check codes again in case the vanos are stuck when cold .
You have timing of the cams but also the trigger wheels but I’m sure they know that.
Keep us posted

Ok I got the belts looked at and the garage had to adjust the tensioner on aux belt and also the power steering belt as well,the car is running a lot better than it did and not so bad on cold start, I will run it for a few few weeks and see if it clears completely if it doesn’t then I will get a diagnostic machine on it to clear the codes when hot and hopefully that will solve it, Thanks for all the help it’s greatly appreciated.......Alistair.