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Discussion Starter · #181 ·
I cleaned my brother's EGR valve on his Civic and it's horrific, almost completely blocked up. Had to chisel the crud off it was so bad. Fortunately it very easy to access and remove, almost the same for the CRV although it had two lower bolts that were very difficult to access.

I was looking into doing it with the XF but I'm sure it's quite a time consuming job to access and remove and I'm sure there's two of them as well on each side? Quite possible that they didn't bother, but certainly something with doing from my experience.
That's interesting, because I've just been looking at the telemetry readings on my phone from the Autel 200, and I've spotted a few differences from the readings I used to get prior to having the actuator changed. They point to the EGR valves (yes there are two).

These are today's results, (with the values pre-actuator swap in brackets). All these are at idle, 700 rpm.

  • EGR - Exhaust Gas Recirculation - (Bank 1) - Commanded: 28.6% (0%)
  • EGR - Exhaust Gas recirculation - Commanded (I assume this is Bank 2 but it doesn't actually say) - Also 28.6%, previous two readings were zero but I have had older readings of around 18%.
  • EGR Valve Position (Bank 1) - 33% (4%)
  • EGR Error -Bank 1 99.7% (95%), Bank 2 99.6% (95%)
  • Calculated Load Value (of what I'm not sure) - 27% (14%)
  • Mass Air Flow - 0.02%, have had similar readings before but the previous two readings were 18% and 19%.
Now I don't know enough about them to be able to interpret the readings but hopefully they will help the garage. Clearly something happening with the EGR valves though. Looking at the first two, I wonder if 0% meant that the valves were more or less completely blocked, and 28.6% means they're a little clearer now than they were?

I did check and clean the MAF sensor recently but it was very clean to begin with.
 

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Discussion Starter · #183 ·
Well I'm done with the original garage anyway. The one it is going in to next are Jag approved and very highly rated by those who have used them. Not cheap, but then there's no point keep paying somebody who doesn't know what they're doing or not following my instructions.

I'm going to go ballistic if this does turn out to be the EGR valves as I asked twice for them to be checked. I always put everything in writing as well, including any points I think are relevant or might help with diagnostics.

He told me he was well clued up on the 3.0d engine but the penny dropped when it came to fit the new actuator and he didn't know where it went, because initially he rang me and told me I'd bought the wrong part. Looking at the one that came off, I don't think there's anything wrong with it. I never really did think it was the actuator.
 

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Discussion Starter · #184 ·
Maybe ask the garage to show you a photo of each EGR off to see just how bad they are. World also increase the chance that they'll actually have to do it!
I just read your post on the Civic, along with a number of other EGR related threads. Those photos are horrendous. Do you have any idea what the mileage was on that car?

Must admit I've never really given the EGR valves much thought, but if they can become that clogged that easily then they're definitely a contender. Also reading some of the symptoms, rough idling, starting problems...

While I don't have problems starting as such, it did used to fire up instantly, now it needs to turn over a couple of times. The idle is slightly rough when I stop after the RP problem rears its head, but settles down after a few seconds. And based on my little survey earlier, I seem to average around 10mpg less than most other owners with the same engine. My research all seems to suggest that all these can be caused by blocked EGR valves, although I do acknowledge that it could be something else.

It's interesting that after adding the Oilsyn additive I didn't get the RP issue for a few days, and even then only after pushing it to 4500 rpm and the 2nd gear indicator turning amber, and for the first time I managed to complete a forged regen and drop the soot level below 20 grams. That, and the different readings on the Autel diag may suggest that the additive has worked to a point anyway, and cleared them slightly. I wonder if it's worth trying again with a good dedicated EGR cleaner?
 

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I'm always in two minds about cleaners that have to work their way through the combustion process, but then I observed from my own tests that Archoil AR6400-D Max did indeed appear to lower the temperature required to burn off soot. Only for a limited time though and I think from memory it was only with that tank full. But it did prove to me that stuff can get through and have an effect.

However, I really can't imagine a cleaner that can clean the hard deposits off an EGR valve that required me to use a screwdriver and hammer to chisel off. The lighter stuff would come off with brake fluid cleaner, but it still needed to be complemented with a cloth and hard rubbing.

I think as a preventative measure from early days a cleaner may help reduce or prevent build up before it goes super hard. Personally, I would still want to remove them and see for myself. I'm not sure if there could be something more accessible and easier to remove that may allow access via an inspection camera?
 

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My Landrover Freelander TD4 was the same inside the inlet manifold and EGR. Thick with hard, crusty black deposits, mixed with a tar like substance. The car was fine one day then next day hardly any power, struggled to get to 30mph. No warning lights, no DTCs. Took me ages and ages to find the issue. The manifold absolute pressure sensor was blocked with this black crap. Cleaned that out (and the manifolds and EGR system) and power restored. But took me days and days of swapping sensors to find the issue. Must admit, I did remove the EGR system and fitted a blanking plate on that car... Was years ago.
 
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Oh that's a good point that I'd forgot about with the Jag, if the EGR valves are getting clogged up then would you not expect the MAP sensor to start getting clogged up as well? Bonus being it's a 10 second job to check the MAP sensor!
 

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Oh that's a good point that I'd forgot about with the Jag, if the EGR valves are getting clogged up then would you not expect the MAP sensor to start getting clogged up as well? Bonus being it's a 10 second job to check the MAP sensor!
Thought there was some Deja Vu going on lol

 

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Discussion Starter · #190 · (Edited)
Yes, the claim is often that the additives remove deposits etc. but I often wonder if that is so, where do those loosened deposits end up? Could they come off in lumps and block something else a little further along?

This Oilsyn stuff seems to be like a premium version of Archoil from reading the accompanying literature, and I have to say that since adding that, this is the first time I've been able to do a successful regen, and it's the first time that I've been able to accelerate up to 4500 revs without it dropping into RP mode. After speaking to the manufacturers, a 400ml can of Carbon Code DPF/Turbo Doctor was added to 30L of fuel, and 125ml of ReleaseTech Power Clean added to the engine oil, which you run for 600+ miles then drain the oil (I've only done about 250 of the 600 miles so far). As I'm going to change the oil and filter anyway after it's been in the garage, I thought I might as well try them.

It is only since then that I have been able to accelerate up to 4500rpm without RP kicking in, and for a couple of days prior to that without it kicking in at all despite my best efforts to try to trigger it, mostly to see what fault codes I get when it does happen (same codes as it turns out). But it could suggest that this stuff is working and it's starting to help to clean whatever part is sticking or clogged up. After all, that is what it's supposed to do. Details of the products here, click the "Tech Sheet" buttons for a full description. Either they work or they don't.

Oilsyn – Lifting the Lid on Fuel & Oil Additive Market

On refilling I added the Archoil 6400 again. I haven't had any DPF warnings since I started using it, just the issue of it not regenerating, but I have been doing manual forced regens to combat that until it goes in. I'm still going to get these EGR valves checked no matter what as it's the only way I will know for sure what condition they are in.
 

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Discussion Starter · #191 ·
Oh that's a good point that I'd forgot about with the Jag, if the EGR valves are getting clogged up then would you not expect the MAP sensor to start getting clogged up as well? Bonus being it's a 10 second job to check the MAP sensor!
Yes that's probably worth a look, although it's supposed to have been checked.

I've got a 100mile run to do at some point this week so I'll see if that improves things any further.
 

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Discussion Starter · #192 · (Edited)
I went out again today, took it easy for 10 minutes so that the car had warmed up, and hit it. RP mode tripped in straight away at 2000rpm, so I just turned around and came back again.

Based on the above comments I then removed and checked the MAPT sensor (I've always referred to it as MAPT to avoid confusion with MAF).

Here are a couple of photos - remember this was supposed to have been checked by the garage a few weeks ago:

Household hardware Auto part Metal Magenta Electronics accessory


Laser pointer Jewellery Auto part Wood Metal


Although the hole looks reasonably clear, I used a wooden cocktail stick to carefully clean it inside and as much crud came out as you can see on the top. I've cleaned it up with Millers Eco-Boost, having realised I'm out of WD-40, and I'm now just waiting for it to dry out before refitting it. Hopefully I haven't damaged it, but might order a new one anyway.

Most of it was soft enough to wipe away, but I had to soak the top for a couple of minutes and rub it to clear it completely. I left the 'hole' to soak in Millers for 20 minutes then emptied it and dried it on the radiator before refitting. Hard to see, but it looked like there could still be a bit of gunge in the bottom of the hole in the sensor area, but I don't want to damage it.

This could be good news in a way, because if the MAPT sensor is this bad, who knows what the EGR valves are like.


UPDATE:
Refitted the sensor, took it out for a short motorway run, 6 miles or so to 1st junction, and got it up to 4500rpm in 3rd gear - and it held for around 25 seconds, then I had to slow down due to traffic. When I accelerated again from 2000 revs, RP cut in again almost straight away.

Turned around and on the way back I took it up to 4500rpm again, this time in 2nd, and it held for around 30 seconds and I had to back off again. I've never been able to accelerate for more than a few seconds before at around 2800-3000 rpm before the RP problem kicks in.

Prior to cleaning the MAPT sensor there was always a slight lag when accelerating, and that's gone. Virtually no lag at all now, maybe a small fraction of a second.

To me, all this indicates that it's definitely clogged up somewhere and the EGR valves are probably favourite. I'm going to contact the garage now, ahead of it going in on Monday and make sure that removing and checking/cleaning those is on the jobsheet.
 

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Discussion Starter · #193 ·
Incidentally does anybody have the part number for the MAPT sensor? I had a quick look on ebay, and apart from a used one I can't see anything that looks the same shape as mine.
 

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Discussion Starter · #196 ·
Thanks John, much appreciated. That definitely looks like the part. Given the amount of crud that came out, and the fact that there still appeared to be some left in the bottom of the hole, which isn't really accessible without risking damage, I think it makes sense just to swap it out.
 

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Discussion Starter · #198 ·
A couple more observations. I checked the MAPT sensor again, just to see how quickly it might be oiling up as the oil on it yesterday was wet, as opposed to dry soot. I'm not sure if that's normal or not but I gave it another quick clean, hopefully got some more of the stuff out of the inner part of it.

Went out again, got the RP issue again but on decelerating after hard acceleration for a few seconds. I stopped and switched off for a couple of minutes to clear it, then did a couple of short motorway runs, about 6 miles between 2 junctions, mostly in 3rd gear in Sport+Race mode. At one point, on turning back I flatlined it for a couple of minutes in 2nd. I did that trip there and back each way twice, so around 25 miles in all, and never hit the PR issue again.

Cleaning the MAPT sensor has undoubtedly made a big difference, and I'm wondering if the Oilsyn additives are actually working and gradually cleaning the engine up. I did think the engine was louder when I got off the motorway on the way home, not sure if it was my imagination or maybe the hard acceleration has caused e a leak at the manifold (or even elsewhere), but I had a quick look when I got home with a torch and could not see any leaks.

I did spot a braided pipe on the left (nearside) of the engine that looked lightly saturated in oil, and it was wet and oily to the touch, so possibly a small leak there. No dripping oil or anything like that though. Hopefully I'll find out properly next week.
 

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A couple more observations. I checked the MAPT sensor again, just to see how quickly it might be oiling up as the oil on it yesterday was wet, as opposed to dry soot. I'm not sure if that's normal or not but I gave it another quick clean, hopefully got some more of the stuff out of the inner part of it.

Went out again, got the RP issue again but on decelerating after hard acceleration for a few seconds. I stopped and switched off for a couple of minutes to clear it, then did a couple of short motorway runs, about 6 miles between 2 junctions, mostly in 3rd gear in Sport+Race mode. At one point, on turning back I flatlined it for a couple of minutes in 2nd. I did that trip there and back each way twice, so around 25 miles in all, and never hit the PR issue again.

Cleaning the MAPT sensor has undoubtedly made a big difference, and I'm wondering if the Oilsyn additives are actually working and gradually cleaning the engine up. I did think the engine was louder when I got off the motorway on the way home, not sure if it was my imagination or maybe the hard acceleration has caused e a leak at the manifold (or even elsewhere), but I had a quick look when I got home with a torch and could not see any leaks.

I did spot a braided pipe on the left (nearside) of the engine that looked lightly saturated in oil, and it was wet and oily to the touch, so possibly a small leak there. No dripping oil or anything like that though. Hopefully I'll find out properly next week.
The engine/exhaust is noticeably louder during a DPF regen.
 
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Discussion Starter · #200 ·
That's interesting. I've never actually noticed before, but then it hasn't been regenerating due to the RP issue. I'll check with the Autel later, see if anything else comes up but it's definitely far better since I cleaned that sensor.
 
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