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Hi guys, long time lurker - first time posting.

move recently bought a 2010 xf-s portfolio with 86k miles and I’m thrilled with it so far.

everything seems to be in good order but I have noticed that during the first minute or so from a cold start the acceleration upto 2.5k rpm has a few flat spots. This seems to clear itself but I still feel a hesitation when the secondary turbo kicks in.

I have no eml’s on, no strange noises. Is this common on the 3.0d engine?

would appreciate to hear if you’ve experienced this and if it’s anything to worry about.

thanks.
 

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Hi Lomond (live near Loch Lomond perchance?). Welcome to the forum.
I had a 2010 XF-S for 5 years but don't remember such flat spots. But if you are definitely linking it with the opening of the secondary turbo, there is a well-known and well-documented issue with the secondary turbo valve actuator - a small vacuum actuator that is a relatively inexpensive replacement/fix. It may be this starting to stick.
But first check some of the simple things like the air filter (is it dirty?), the induction pipework for loose connections or cracks. And it's quite an easy job to clean the two MAF sensors (one in each of the ducts coming off the LHS of the filter box.)
 
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Welcome Lomond,

I also had a MY2010 XF-S, like yours with UB paint and volan alloys. Like John however, it never had any engine problems with flat spots. A fantastic car that is still missed, hope it gives you many happy motoring miles, once you get it sorted. Does sound like a possible sticking actuator on the secondary turbo though.

Oh, a picture or two is always good :)
 

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Hi Lomond (live near Loch Lomond perchance?). Welcome to the forum.
I had a 2010 XF-S for 5 years but don't remember such flat spots. But if you are definitely linking it with the opening of the secondary turbo, there is a well-known and well-documented issue with the secondary turbo valve actuator - a small vacuum actuator that is a relatively inexpensive replacement/fix. It may be this starting to stick.
But first check some of the simple things like the air filter (is it dirty?), the induction pipework for loose connections or cracks. And it's quite an easy job to clean the two MAF sensors (one in each of the ducts coming off the LHS of the filter box.)
Thanks for the reply. My next job (time permitting) was going to be replacing the throttle to intake manifold gaskets so I had planned on cleaning and perhaps swapping the MAF sensors.

had a quick look at the pipe work but I’m feeling a little daunted just looking at the 3.0l lump. I know my way around an engine but I’ve not much experience on things this complex/cramped.

car is running well after the initial start up so not too concerned. I maybe have read too many threads on this forum for my own good!
 

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Welcome Lomond,

I also had a MY2010 XF-S, like yours with UB paint and volan alloys. Like John however, it never had any engine problems with flat spots. A fantastic car that is still missed, hope it gives you many happy motoring miles, once you get it sorted. Does sound like a possible sticking actuator on the secondary turbo though.

Oh, a picture or two is always good :)
Thanks for the reply. I’ll get a few pics posted later.

I’ll have a look at the secondary turbo. Is it possible to remove/clean the actuator in situ?
 

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Finally had the chance to do some digging...

cleaned the MAF sensors, the bottom sensor was obviously dirty so did my best to clean it and swapped it with the cleaner top one (Which was spotless) - this seems to have solved the hesitation between 2-3,000 rpm!

I also renewed the two gaskets between the throttle body and valve covers but doubt this would do much.


also I had a look at the compressor shut off valve and it was gleaming with no signs of dirt/oil anywhere on the actuator arm so I just left it as is.

wrt the dirty MAF - I’ve ordered a 2nd hand job from eBay so will swap it out for this as an experiment. As I say the car seems to be much smoother after the work I’ve done 👌
181773
 

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Finally had the chance to do some digging...

cleaned the MAF sensors, the bottom sensor was obviously dirty so did my best to clean it and swapped it with the cleaner top one (Which was spotless) - this seems to have solved the hesitation between 2-3,000 rpm!

I also renewed the two gaskets between the throttle body and valve covers but doubt this would do much.


also I had a look at the compressor shut off valve and it was gleaming with no signs of dirt/oil anywhere on the actuator arm so I just left it as is.

wrt the dirty MAF - I’ve ordered a 2nd hand job from eBay so will swap it out for this as an experiment. As I say the car seems to be much smoother after the work I’ve done 👌
View attachment 181773
Thought that was my old car, but my side vent was silver.

Still looks lovely though(y)
 

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Thought that was my old car, but my side vent was silver.

Still looks lovely though(y)
Cheers Rigger, the car is a credit to its former owners - hopefully it’ll remain that way...
 

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Hi guys, long time lurker - first time posting.

move recently bought a 2010 xf-s portfolio with 86k miles and I’m thrilled with it so far.

everything seems to be in good order but I have noticed that during the first minute or so from a cold start the acceleration upto 2.5k rpm has a few flat spots. This seems to clear itself but I still feel a hesitation when the secondary turbo kicks in.

I have no eml’s on, no strange noises. Is this common on the 3.0d engine?

would appreciate to hear if you’ve experienced this and if it’s anything to worry about.

thanks.
Just wondering if your problem was solved by what you have done for future reference. I wondered as the fault sounded very MAP sensor ish. Anyhow I hope all is now well.
 

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Just wondering if your problem was solved by what you have done for future reference. I wondered as the fault sounded very MAP sensor ish. Anyhow I hope all is now well.
After replacing the bottom MAF sensor, replacing the two circular gaskets that join the throttle body to the cam covers and cleaning the MAP sensor the flat spot is barely noticeable. Unsure which made the most difference but the MAF I replaced was badly soiled.I was unsure how hard to go cleaning the MAP so I just cleaned the outermost ring with a cloth and sprayed plenty of contact cleaner into the hole.

had a look at CSOV but it looked spotless so didn’t pull it. Next chance I get I will remove it to inspect properly.
 

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After replacing the bottom MAF sensor, replacing the two circular gaskets that join the throttle body to the cam covers and cleaning the MAP sensor the flat spot is barely noticeable. Unsure which made the most difference but the MAF I replaced was badly soiled.I was unsure how hard to go cleaning the MAP so I just cleaned the outermost ring with a cloth and sprayed plenty of contact cleaner into the hole.

had a look at CSOV but it looked spotless so didn’t pull it. Next chance I get I will remove it to inspect properly.
I had issues with MAP sensor recently. Can you read MAP and boost pressure with ignition on and engine off, then at idle? It could be done using an OBD2. Mine was working with no fault codes but the readings were off and fluctuating. Wondering if a bad MAP causes ECM adjusting EGR and Left turbo incorrectly leave you with those flat spots.
 

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Discussion Starter #12
After replacing the bottom MAF sensor, replacing the two circular gaskets that join the throttle body to the cam covers and cleaning the MAP sensor the flat spot is barely noticeable. Unsure which made the most difference but the MAF I replaced was badly soiled.I was unsure how hard to go cleaning the MAP so I just cleaned the outermost ring with a cloth and sprayed plenty of contact cleaner into the hole.

had a look at CSOV but it looked spotless so didn’t pull it. Next chance I get I will remove it to inspect properly.
I had issues with MAP sensor recently. Can you read MAP and boost pressure with ignition on and engine off, then at idle? It could be done using an OBD2. Mine was working with no fault codes but the readings were off and fluctuating. Wondering if a bad MAP causes ECM adjusting EGR and Left turbo incorrectly leave you with those flat spots.
cheers Hamed, I’ll check those readings later.

I had considered swapping the MAP for a new sensor just to make sure, but didn’t want to start throwing money at the car without a clear idea what was wrong.
 

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cheers Hamed, I’ll check those readings later.

I had considered swapping the MAP for a new sensor just to make sure, but didn’t want to start throwing money at the car without a clear idea what was wrong.
Checked with the obd reader and the MAP reading was stable at 98kpa with engine off and at idle (it did change when revving the engine).

Not sure what to look for with a MAP sensor but it was not fluctuating.


initially after turning the engine on and revving it, it was very lumpy up until 2.5k to 3k rpm. This resolved itself after a few minutes of running.
 

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Checked with the obd reader and the MAP reading was stable at 98kpa with engine off and at idle (it did change when revving the engine).

Not sure what to look for with a MAP sensor but it was not fluctuating.


initially after turning the engine on and revving it, it was very lumpy up until 2.5k to 3k rpm. This resolved itself after a few minutes of running.
It should read about 150kpa at idle. You can try it with a warm engine. It shouldn’t be lumpy when engine is warm. I would recommend cleaning with electric contact cleaner if you haven’t done already.
 

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It should read about 150kpa at idle. You can try it with a warm engine. It shouldn’t be lumpy when engine is warm. I would recommend cleaning with electric contact cleaner if you haven’t done already.
Cleaned with contact cleaner but didn’t want to poke anything into the hole in the middle - I don’t know how much force the sensor can take!

A new Land Rover part is £60 so may just get one and see if that makes a difference.
 

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Cleaned with contact cleaner but didn’t want to poke anything into the hole in the middle - I don’t know how much force the sensor can take!

A new Land Rover part is £60 so may just get one and see if that makes a difference.
And thanks again for your reply!
 

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And thanks again for your reply!
no worries. Mine was reading boost at 96kpa (map-barometric) at idle instead of 50kpa. So yours seem alright if MAP reads 98kpa with engine off.
Wondering if that lumpy behaviour is due to a leakage or an sticky turbo arm or sticky egr valve and if it has anything to do with the flat spot. I.e. ECM struggling to adjust the boost.
 

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Discussion Starter #18
Quick update - fitted new map sensor yesterday and it made no difference. Still fluttering through to 2,700 rpm.
 
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