Hi

2007 RRS TDV8, 152K miles

I’m having a problem with the car being lumpy and smoking at start up. There is no smoke when driving, either accelrating or decelerating, fast or slow driving.

When the car is being lumpy, it is regular and you can feel it through the body and if you select drive then it gets worse and if you try and drive then the car surges and stops, surges and stops as the clutch bites I presume. This latter surging observation is not present when there is no lumpiness or smoke.

I have no coolant loss and no blue smoke

The lumpiness and smoking does clear after a time, 30, 150-180 and 300 seconds all seem to be times over the startups I have monitored, nothing conclusive but caught my attention when video and trace capturing whats happening in what sequence

I have a Gap IID bluetooth and have logged any faults, once only an imbalance fault was logged on the intakes and investigation found that the angled connectors from the MAF’s had aged and split, these have been fixed and both MAF’s have been cleaned as one looked dirty but I wasn’t sure so I cleaned it with the proper spray

I used the IID to look at various readings, around the MAF’s, EGR’s and all the sensors I could find and attache two of the traces that look at the EGR position and the temperature settings of the intake. Engine oil and water andtransmission oil. I have done a few of these when ticking over, when driving, when restrating after various times

The fault persisted so I then used Wyns Turbo and EGR cleaner, first application was the spray into both intakes (after the MAFs), then a tank treatment with the Wyns turbo and EGR cleaner, the the spray again into the intakes and finally the Wyns diesel system cleaner in a 20L tank fill.

The initial trace showed EGR1 seemingly smooth in operation and modulating as I would expect when operating car ie ticking over, hot, cold, accelerating and decelerating. This all based on received knowledge googling and talking to a couple of friendly mechanics. EGR2 was a different trace, it wasn’t in sync with EGR1, it was very spiky, oscillating around and not always following EGR1, so this was suspect.

After the cleaning process EGR2 operation is following EGR1 much closer, it remains spiky around the EGR1 values and when you stop the car, the EGR’s modulate to their extenst (0-100%) but EGR2 does not reach 100%, it looks around 70-80% modulation

After watching the smoke and driving the car with no smoking when driving I am confident (hopeful) it is not the turbo’s, not the torque convertor or clutch. The IID says the torque convertor is open, closed and regulating as I understand again from receive knowledge.

So I’m piecing all this together and thinking I have an EGR problem, I have improved EGR2 operation, to modulate closer with EGR1 and am not sure if more cleaner will work out the issue or I am at the point of replace/blank out the EGR’s

What would help is knowing if my EGR’s are modulating properly, I have no benchamrk to compare their operation. I can say that they are behaving differently to each other when driving but they do now follow much closer in opening and closing and when I accelerate they both close fully as I believe they should.

Could I ask anyone that has a Gap IID if they could do a live value trace on their car of the same items, I am primarily interested in the EGR position and how they fluctuate when idling, driving and the various accel/decel/cruisng etc

The two traces are from this morning, I have more traces and supporting video of the lumpiness and smoking if needed to help any thoughts or suggestions

I’ve just had a year and half off work (money is now tight) due to bad health and need to be as certain as possible before we start changing parts as an initial quote to change the EGRs was nearly £800 excluding labour to replace the EGR’s (genuine LR)

Thanks in advance

Click image to enlarge

Click image to enlarge

The valves can temporarily be blanked off to isolate them

Wouldn't advise driving like that, but would see if it cures the rough startup

Had one very similar just last week. Very rough, smokey, wouldn't take throttle
Admittedly, it did log a MAF fault, but upon blanking, it was perfect. Valves were removed, and the valve head had completely detached itself from the actuator...

I saw that procedure in the LRO mag a few editions back and it seemed nearly the same amount of work to get in to blank off as it is to get and change, so I thought if I could compare the EGR valve live value trace from someone elses car that is working first, it gives me a better idea that there is a fault. Save a double bubble on labour costs

That one you just changed with the detached head, just thinking because mine seems to clear after a period then doesn't this suggest the head is intact otherwise it wouldn't change what ts doing and would be rough all the time. I'm only thinking aloud and happy to be corrected, i am in limited knowledge mode on this one, never dealt with EGR's before

[Edit] - Hi Mike, I've just reread the LRO mag and looked under the bonnet and they are closer to the top than I initially thought I had read, will have a look at this temporary blanking again, to aid the diagnosis. Forget my comment on double bubble labour, I'm off on that one.

It would be useful to still compare, if anyone can help with the IID live trace of the two valves, its handy info to know in my book

If this blanking shows the valves are the culprit, has anyone done the permanent EGR delete and had them removed and coded out and also passed the new MOT?

That one would run relatively well once warm, albeit a bit laggy at the bottom end

Live values were 100%, and at no point did any diagnostics point towards an EGR issue. That was an educated guess with a little experience thrown in

LOL, I wish we were not at the southern end of the country, need some of that experience

Could I ask are the traces I put in post 1 typical ie EGR2 spiking all over whilst EGR1 is smoother, albeit it also jumps around at times, just trying to gauge what you mean by the live values were 100%

Live values were 100%, as in the actual positions were a perfect match for the commanded positions

The valve movements should be fairly smooth, and actual position should be as close as possible to the commanded.

Electronically, my valves were working fine, with no diagnostic issues. It was a pure mechanical fault, with the valve head fallen off, which the diag would not have shown up

Thanks Mike, I'm taking my spiky trace is not a good sign.

Last question please, I cannot see on the IID an option to command the valve postions, only a positional trace, am I missing something?

Hi Mike

Thanks for the info and the push to boost my bravery, there seems a lot of wires, tubes and connectors on top of a TDV8!!

Apologies for the delay, tied up at hospital for me and my Dad now in his fourth round of chemo so we are travelling a bit to see him.

On the car, I took the plunge and got to the two connector pipes from the EGR's and the air induction on top. The RHS was very clean but the LHS was much more dirty and i noticed the outer lip of the ribbed tube had been squashed slightly, not sure if I did this on removal but the soot was undisturbed so this finger sized lip could have been there a while, we have had the car since 2010 and no work on the EGR's has been required, so I do not know.

We did have the thermostat housing changed 3 year back as it was leaking, so this may have involved removing the induction and associated pipework, not really sure

What I did was to fabricate a metal blanking shim for both of the EGR end holes and all went back together quite easily, immediate improvement, no lumpyness, no smoke and drives really well, so to summarise

Both EGR's are still modulating, after all the cleaning I did, EGR2 is following better EGR1 but EGR2 remains spiky in operation (see traces posted previously)

The car is driving OK, its our daily drive for the wife, kids and dog and keeps them out of my defender

There are no faults on the car with these shims in place, the IID has been used to check all this and to see that the EGR's are still modulating albeit the gases can not reach the inlets anymore.

How long can it be driven like this, does anyone have any experience of just blanking them out but still have them operating

An initial thought would be to drive until the MOT is due (Mar 19) and if it fails on emmissions then remove the blanking shims and get the EGR's replaced at that time. This thought process is guided by my bank account which is complaining after a year off work

Is this a sensible thought or am I creating a bigger issue by driving in this way

Thanks for all the help thus far

bump, would be good to know if this is a reasonable way (see previous post in thread) to approach this or am I creating an issue