Thread: EGR valve fault and replacement......

Gday , sounds like fun not , did you take the egr coolers out as well ? as i take it the clips you mention are the ones connecting cooler to ex/pipe. Did you have a look inside the intake manifold at the other end of the egr tube wher the butterfly is to make sure it is not full of black gunge . Any way thanks for post . Al

Hi Al,
I replaced the water manifold on top of the engine a few months ago so I sort of already knew what i was up for with the clips, and the ones I'm talking about are you are correct the ones on the end of the EGR tube and the cooler, there is another one on the back of the EGR cooler which is in a plick of a place, the handle of the small vise grips just fit in between the cooler and the inner wing.
The butterfly housing inlets did have some black gunge on it and this had also blocked one of the sensors which got fixed at the time, the engine ran a lot better after the sensors had been cleaned with brake cleaner.

With your EGRs now working it is time to blank them - as long as the egrs actually work you can blank your car without issue.

If you don't it will not be long before you have to replace the EGRs again.

Garry

Hi Garry,
I wondered about this, I was of the impression that the valves had to be in place and working and not blanked off. So as long as the valves are fitted and working the tubes can be removed. So what is the difference between a pre and post 07 model? So on a pre 2007 model you can blank off and remove the tubes and leave the valve disconnected electrically, and not have the engine alarm light on, is that right?
On a post 2007 model the tubes can be removed and the valves left connected electrically and no engine alarm light visible with no detrimental effect on the engine.
What is the valves mode of failure? Does it stick/ seize. Mine appeared to be in quite good condition overall so I've assumed that the fault was electrical internally.
If I now disconnect the EGR valve from the inlet manifold, leave the valve in place and electrically connected, what is to stop the valve failing electrically again? Or is it do do with the valve mechanism itself stickng or seizing? Hot gas passing the valve causing the problem. If I can take these valves out of the loop and not effetc the engine performance infact possibly improve it that would be great.

I have a mid 07 MY07 (I guess one of the last MY07) vehicles.

My EGRs first failed this time last year with the EML showing bit no issue with performance so they had failed in the closed position (like a blanked engine). I cleared the codes a couple of times with my Scanguage and all seemed well.

Mid year the light came on again and again no performance issue but the codes would not clear with the now basic Faultmate. As well on a couple of drives the engine started running like crap. A sign that the EGRs were not completely seized but were locking from time to time and were no sometimes sticking open allowed exhaust gases into the engine on the power side and choking the engine.

Time to do something I ordered new EGRs from the UK at a good price. While waiting I started some serious research and concluded that I was going to get my knuckles bruised changing the EGRs.

When the new EGRs arrived for some reason I just connected them to the connectors with the old ones still connected to the exhaust - they were closed at that time and noticed that the EML did not come back on. I have a length of freeway nearby and went for a drive which made these new EGRs cycle through their full process and no EML. I stopped and switched off and watched the new EGRs cycle through their cleaning process. So with these connected and the old EGRs in place but closed was the same as having the engine blanked.

So I ordered a BAS blanking kit and blanked the engine. I have mounted the new EGRs on top of the engine cover and when I get around to making a loom extension I will mount them in the secondary battery box area in front of the driver.

I have been running my car like this for 8,000km and 6 months with no more codes or EML lights.

The EGRS can lock open but more often than not the hot hostile environment kills them electrically and then the movement also dies. While the blanks go on the inlet intake side of the EGRs really they should go on the exhaust side to protect the EGR from the exhaust however to do this would mean going through all the hassles of undoing the EGRs etc.

If I unplug the loom from the new EGRs and put them into the old EGRs the codes and warning lights are back straight away.

The little black package is one of the new EGRs wrapped up in bubble wrap and gaffa tape.



Garry

A bit more info for what its worth , I did the same as Garry but with my working egr,s in place , all seemed ok with no visual alarms etc , but with a slight increase in fuel usage , after about 4 weeks i did a system check with my faultmate and found a reading of " excessive egr flow " under engime managment , i cleared this and checked it a week latter and it was back again , same procedure and it came back again .

My theory is that the MAFF is picking up excess air flow with the blanks in place when the ECU wants the EGR to operate, and the removed butterfly should be closed or partualy closed . I am not sure what this does to the fueling at this point ?.

As i dont want to risk a Limp home mode as i live in the country or damage the eng ,i put the egr system back as it was untill i can ascertain if i have a problem with excessive egr reading or not and and in the meantime keep the intake manifold clean , after which i have had no more excessive EGR readings . PS, My RRS is a January 2007 build date .

Hi Al,
I had heard there was a reason why you couldn't do this mod on the "later than 7A" engines, this could possibly be the reason. Saying that Garry mentioned that his egr valves had stuck in the closed position which as he says would have given the same effect as having the blanks in. Garry was using the basic Faultmate which I'm not sure if it has the facility to check for excess O2. I'm going to assume that the engine light didn't come on this was just a case of you checking for checking sake when you noticed the slight increase in fuel consumption.
When I had a 3.0l Nissan Patrol at one point and this had similar EGR issues, again there was a blanking kit you could buy, however there was quite a complex procedure to change the engine management program to accommodate the lack of EGR valve pipe to the manifold. If you didn't do this there was this theory about engine overheating and all sorts of bad stories, something like yourself I didn't want to risk.
When I sold the vehicle at 167k klms the head was pretty gunged up and I always wondered if it was worth it, the head in the end would have to be cleaned out which I assumed required the head removing from a perfectly running engine (sort of), which seemed a pity.
I suspect that oil quality will play a huge part in the gungeing up process, my vehicle was serviced twice by non LR agents prior to me buying it which could possibly explain some of the excess gunge I found a few months ago when I replaced the water manifold.

Gday All,

I tried to blank my EGR's on the 08 TDV6, and the car ran fine but had the same intermittant EGR fault which would put the car into limp mode.

In the end I put the system back and will just clean the intake side every service or so.

I did read on the UK site that Bell auto's had come up with a software fix for the later post 07 models.

I too think its more a MAF reading that is the problem with the blanking.

Cheers Ean