3500-4000 Rev judder

Arryhall · 11th March 2017, 13:45

Ay up. Question for people what know this stuff. If I floor the accelerator on my 1.8T, it accelerates nicely with a growl and Grrr, but then it kind of stalls for a fraction of a second before accelerating again, then another slight hiccup somewhere around 5000rpm. I know nothing about cars and engines and don't want the garage fobbing me off with nonsense. Is this a fueling thing, a turbo thing, an engine map thing or what? Anyone experienced anything like this? Is my car about to blow up?
If I accelerate more gently, it's perfectly smooth to the Red line and is smooth back down, it's just when I boot it to get on the motorway or just for kicks. The idle is just a wee bit jumpy, as in maybe 20 rpm fluctuation slowly. Just thought I'd add this info in case it helps.
Thanks people.

Arryhall · 13th March 2017, 15:46

Okay, an addendum. A couple of days ago, I was seeing if the stutter was still there and when it did stutter, the check engine message appeared and the engine management light came on. Everything went off again in about 6 seconds or so, but it did scare the pants off me.
Really getting concerned about this now, as the garage mechanic's attitude is "don't drive it fast and it won't do it." This surely isn't the answer, is it? I've been able to floor every car I've ever had occasionally when the needs have arisen and never had an issue before.

Well, except my Montego, and that just got louder, smokier and judderier, but didn't actually go any faster.

another_clean_sheet · 13th March 2017, 16:25

This does sound like a fuelling problem. The fact that EML came on could be due to low fuel pressure. Is there a T4 guru near you who could read the stored error code?
How much fuel was there in the tank?

Sheraton · 13th March 2017, 16:47

possibly overboost from the turbo - or spark plug gap needs reduced to 0.50 - 0.60

if you can bypass the boost control solenoid and connect the compressor to the wastegate on the turbo you should be able to confirm/rule-out overboost

Paul.

Sheraton · 13th March 2017, 17:18

I've had this problem, when i first bought my car - i know how frustrating it can be and how paranoid it makes you

i'll try and post some pics to explain bypassing the boost control solenoid - it's a simple task when you know how - also if it is overboost it's a cheap simple fix

and reducing the plug gap is as easy - also worth doing on a 1.8t regardless

Paul.

Yorkshire GOC · 13th March 2017, 19:01

On my 1.8 turbo with very similar symptoms and the flashing engine warning light on for a few secs after the judder then all back to normal - it was a failing ignition coil - a T4 would confirm this or you can remove the rocker cover and see if the coil terminals are clean(2 coils for the 4 cylinders) - on one of mine the terminal was carbonised causing the symptoms you describe

Sheraton · 13th March 2017, 19:09

r.e potential overboost - first you should check that the boost control vac hoses are connected and connected to the correct ports

images are not great here

Boost Control Solenoid is on the Airbox

the other ends of the vac hoses connect to the turbo here - as viewed from the left hand side with the airbox removed (easy to do)

zoomed out

the airbox will pull out with a bit of force - pulling from the back towards the front

you don't need to remove the airbox to check the hoses are connected - hopefully the pics can help you locate the connections on the turbo

if you're lucky a hose will just be disconnected and causing overboost.

i'd be inclined to think spark plug gap from your description - i had a stutter recently after converting to a VVC Inlet Manifold - thanks to the Boost Gauge i fitted at the time - i was able to rule out fuel cut due to overboost

I reduced the gap in my spark plugs to 0.60 from 0.80(i think) and she's been great since i give it full beans regularly

and since fitting a K&N panel filter last week i can't help myself

my advice to start then - check hose connections, reduce spark plug gap

if no joy, then it's likely to be overboost caused by a failing Boost Control Solenoid - the grey bit the hoses connect to on the side of the airbox - they fail regularly, i'm on my 2nd replacement in 15k miles

it's an easy fix to bypass the Boost Control Solenoid while waiting on a replacement - connect directly to the wastegate from the turbo

they're relatively inexpensive - £30 ish delivered - and real easy to fit

the other thing that could cause overboost would be a sticking wastegate actuator - easy to check with bicycle pump

oh and it's worth replacing the vac hoses for silicon regardless

Paul.

Arryhall · 13th March 2017, 19:53

Thanks people. I'll have a play with my laptop open on this thread when it isn't raining and cold!
I do get paranoid about engine issues, simply because I just don't know anything about them and always assume anything is going to cost thousands of pounds to fix, or the car will be written off.

Had an odd, grunty, low engine noise on my Honda, turns out the garage suspect it's the valves and or the valve seats burnt out from the LPG valve saver device not operating properly. Easily over £1500 to fix, and several hundred quid just to look to make sure that it is what's wrong. I'd love to do it myself, but if I dismantled the engine, I'd have a car with its' engine in a box forever more! When this happened judder happened on the 75, I thought "Ay up, I've got another engine on its' way out now!" and cried a little.

Sheraton · 13th March 2017, 22:08

Quote:

Originally Posted by Arryhall

Thanks people. I'll have a play with my laptop open on this thread when it isn't raining and cold!
I do get paranoid about engine issues, simply because I just don't know anything about them and always assume anything is going to cost thousands of pounds to fix, or the car will be written off.

Had an odd, grunty, low engine noise on my Honda, turns out the garage suspect it's the valves and or the valve seats burnt out from the LPG valve saver device not operating properly. Easily over £1500 to fix, and several hundred quid just to look to make sure that it is what's wrong. I'd love to do it myself, but if I dismantled the engine, I'd have a car with its' engine in a box forever more! When this happened judder happened on the 75, I thought "Ay up, I've got another engine on its' way out now!" and cried a little.

the K-series is an easy engine to get to grips with

I wouldn't worry too much over this

as it only happens under full throttle - worst case is a fuelling issue (to my thinking

)

just carbon build up could cause the same symptoms - a dose of Redex in a full tank of fuel is also worth doing regardless.

I do suspect you have the same issue i was having - either/both Overboost or a misfire caused by too big of a spark plug gap.

both are easy to diagnose at no cost - assuming you have tools to remove the plugs

and real easy to do yourself

check these vac hoses are connected first

Paul.

Arryhall · 24th March 2017, 12:45

Well! Just heard back from the mechanic and according to him it was a pipe that was loose or had come off or was broken (couldn't make out what he actually said!) from the turbo and now it is fine.

The garage that sold me the car is, however, saying that this isn't covered under warranty as it isn't an engine fault and are therefore not paying for the repair.

The reason I bought the car from a garage was so that it was covered for a couple of months in case anything went wrong. I could have got the same spec car with lower mileage (and not full of water) from eBay for about £650, but I paid the £950 to a dealer, the £300 being an insurance against issues such as this.

Am I wrong in being exceptionally annoyed at this? Afterall, I fixed the leaks and the CD player myself, have done the flushing to clear the heater exchange matrix myself, fixed the light gaskets and didn't just take the car back and demand he did them. I also still have to valet the car to get the mould out of the carpets and get rid of the smell of damp now it is dry, AND make a new boot plate as the wooden one is warped and black from the standing water.

Thinking I ought to have taken this thing back and got one from a member on here. No warranty or anything, but I'd be in the same boat anyway with an extra £300 to fix stuff.

Picking the car up after work this afternoon, and I shall see if it is actually fixed and not just being fobbed off.

11th March 2017, 13:45	#1
Arryhall Loves to post Rover 75 Join Date: Mar 2017 Location: Biddulph Posts: 486 Thanks: 101 Thanked 145 Times in 90 Posts	3500-4000 Rev judder Ay up. Question for people what know this stuff. If I floor the accelerator on my 1.8T, it accelerates nicely with a growl and Grrr, but then it kind of stalls for a fraction of a second before accelerating again, then another slight hiccup somewhere around 5000rpm. I know nothing about cars and engines and don't want the garage fobbing me off with nonsense. Is this a fueling thing, a turbo thing, an engine map thing or what? Anyone experienced anything like this? Is my car about to blow up? If I accelerate more gently, it's perfectly smooth to the Red line and is smooth back down, it's just when I boot it to get on the motorway or just for kicks. The idle is just a wee bit jumpy, as in maybe 20 rpm fluctuation slowly. Just thought I'd add this info in case it helps. Thanks people.

13th March 2017, 19:01	#6
Yorkshire GOC I really should get out more....... Rover 75 connoisseur se v6 auto Join Date: May 2014 Location: Hull Posts: 2,064 Thanks: 1,842 Thanked 623 Times in 469 Posts	On my 1.8 turbo with very similar symptoms and the flashing engine warning light on for a few secs after the judder then all back to normal - it was a failing ignition coil - a T4 would confirm this or you can remove the rocker cover and see if the coil terminals are clean(2 coils for the 4 cylinders) - on one of mine the terminal was carbonised causing the symptoms you describe __________________ She came off the Longbridge Line on 20-05-2003 The Silver Machine was the 13th of 160 Rover 75's to come off the production line that day and is the 100th of 527 Starlight Silver Rover 75 2.5 V6 Connoisseur SE Auto saloons listed in the build records produced world wide.

13th March 2017, 15:46	#2
Arryhall Loves to post Rover 75 Join Date: Mar 2017 Location: Biddulph Posts: 486 Thanks: 101 Thanked 145 Times in 90 Posts	Okay, an addendum. A couple of days ago, I was seeing if the stutter was still there and when it did stutter, the check engine message appeared and the engine management light came on. Everything went off again in about 6 seconds or so, but it did scare the pants off me. Really getting concerned about this now, as the garage mechanic's attitude is "don't drive it fast and it won't do it." This surely isn't the answer, is it? I've been able to floor every car I've ever had occasionally when the needs have arisen and never had an issue before. Well, except my Montego, and that just got louder, smokier and judderier, but didn't actually go any faster.

13th March 2017, 16:25	#3
another_clean_sheet Posted a thing or two Rover 75 CDTI Tourer Join Date: Nov 2014 Location: Great Bardfield, nr Braintree Posts: 1,414 Thanks: 303 Thanked 436 Times in 317 Posts	This does sound like a fuelling problem. The fact that EML came on could be due to low fuel pressure. Is there a T4 guru near you who could read the stored error code? How much fuel was there in the tank?

13th March 2017, 16:47	#4
Sheraton Posted a thing or two Rover 75 1.8t Join Date: Oct 2015 Location: Edinburgh Posts: 1,377 Thanks: 384 Thanked 409 Times in 267 Posts	possibly overboost from the turbo - or spark plug gap needs reduced to 0.50 - 0.60 if you can bypass the boost control solenoid and connect the compressor to the wastegate on the turbo you should be able to confirm/rule-out overboost Paul.

13th March 2017, 17:18	#5
Sheraton Posted a thing or two Rover 75 1.8t Join Date: Oct 2015 Location: Edinburgh Posts: 1,377 Thanks: 384 Thanked 409 Times in 267 Posts	I've had this problem, when i first bought my car - i know how frustrating it can be and how paranoid it makes you i'll try and post some pics to explain bypassing the boost control solenoid - it's a simple task when you know how - also if it is overboost it's a cheap simple fix and reducing the plug gap is as easy - also worth doing on a 1.8t regardless Paul.

13th March 2017, 19:09	#7
Sheraton Posted a thing or two Rover 75 1.8t Join Date: Oct 2015 Location: Edinburgh Posts: 1,377 Thanks: 384 Thanked 409 Times in 267 Posts	r.e potential overboost - first you should check that the boost control vac hoses are connected and connected to the correct ports images are not great here Boost Control Solenoid is on the Airbox the other ends of the vac hoses connect to the turbo here - as viewed from the left hand side with the airbox removed (easy to do) zoomed out the airbox will pull out with a bit of force - pulling from the back towards the front you don't need to remove the airbox to check the hoses are connected - hopefully the pics can help you locate the connections on the turbo if you're lucky a hose will just be disconnected and causing overboost. i'd be inclined to think spark plug gap from your description - i had a stutter recently after converting to a VVC Inlet Manifold - thanks to the Boost Gauge i fitted at the time - i was able to rule out fuel cut due to overboost I reduced the gap in my spark plugs to 0.60 from 0.80(i think) and she's been great since i give it full beans regularly and since fitting a K&N panel filter last week i can't help myself my advice to start then - check hose connections, reduce spark plug gap if no joy, then it's likely to be overboost caused by a failing Boost Control Solenoid - the grey bit the hoses connect to on the side of the airbox - they fail regularly, i'm on my 2nd replacement in 15k miles it's an easy fix to bypass the Boost Control Solenoid while waiting on a replacement - connect directly to the wastegate from the turbo they're relatively inexpensive - £30 ish delivered - and real easy to fit the other thing that could cause overboost would be a sticking wastegate actuator - easy to check with bicycle pump oh and it's worth replacing the vac hoses for silicon regardless Paul.

13th March 2017, 19:53	#8
Arryhall Loves to post Rover 75 Join Date: Mar 2017 Location: Biddulph Posts: 486 Thanks: 101 Thanked 145 Times in 90 Posts	Thanks people. I'll have a play with my laptop open on this thread when it isn't raining and cold! I do get paranoid about engine issues, simply because I just don't know anything about them and always assume anything is going to cost thousands of pounds to fix, or the car will be written off. Had an odd, grunty, low engine noise on my Honda, turns out the garage suspect it's the valves and or the valve seats burnt out from the LPG valve saver device not operating properly. Easily over £1500 to fix, and several hundred quid just to look to make sure that it is what's wrong. I'd love to do it myself, but if I dismantled the engine, I'd have a car with its' engine in a box forever more! When this happened judder happened on the 75, I thought "Ay up, I've got another engine on its' way out now!" and cried a little.

24th March 2017, 12:45	#10
Arryhall Loves to post Rover 75 Join Date: Mar 2017 Location: Biddulph Posts: 486 Thanks: 101 Thanked 145 Times in 90 Posts	Well! Just heard back from the mechanic and according to him it was a pipe that was loose or had come off or was broken (couldn't make out what he actually said!) from the turbo and now it is fine. The garage that sold me the car is, however, saying that this isn't covered under warranty as it isn't an engine fault and are therefore not paying for the repair. The reason I bought the car from a garage was so that it was covered for a couple of months in case anything went wrong. I could have got the same spec car with lower mileage (and not full of water) from eBay for about £650, but I paid the £950 to a dealer, the £300 being an insurance against issues such as this. Am I wrong in being exceptionally annoyed at this? Afterall, I fixed the leaks and the CD player myself, have done the flushing to clear the heater exchange matrix myself, fixed the light gaskets and didn't just take the car back and demand he did them. I also still have to valet the car to get the mould out of the carpets and get rid of the smell of damp now it is dry, AND make a new boot plate as the wooden one is warped and black from the standing water. Thinking I ought to have taken this thing back and got one from a member on here. No warranty or anything, but I'd be in the same boat anyway with an extra £300 to fix stuff. Picking the car up after work this afternoon, and I shall see if it is actually fixed and not just being fobbed off.