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Map sensor cleaning.

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Nikolaj   
Sun Oct 20 2019, 07:45pm
Joined: Aug 29 2019
Member No: #4047
Location: Roskilde
To get the full picture, the car had been runing OK for a month after I got the glow plug issue fixed for now. (5 of 6 working)

We were going 230 km up in Sweden, after lunch (an hours drive) I put it in "S" to get a quick launch out on the motorway, but half way down the ramp I got the engine fault and limp mode, which was quite annoying.

Thinking it could be the glow plugs playing up again, I tok the next exit, stopped the engine for a few minutes, and disconnected the glowplugs.

Engine fault announced itself again after 15 sec., but beeing out of limp mode, we could continue to our destination.

Pattern seemed to be, always limp mode from cold, but when warm still engine fault, but out of limp mode. Didn't bring Diabox, since it had behaved well for many weeks.

Back home I read codes out, and got almost same series of codes as an earlier post P010A Air flowmeter 2 (front) signal fault : Flow too high, and P0299, P2279, P0069 - Turbo pressure signal.

I switched the flow sensors at the airfilter, and deleted error codes, to see if it changed anything, well it did, but not as expected, actually only the P0069 (Turbo pressure signal fault : Turbocharging pressure / atmospheric pressure consistency ) came back, so turned my attention to the EGR valves, as they seemed to be the issue in other posts.

Both EGR valves passed the diabox test, but the "click" sound was a bit different between front and back, and EGR valve position was a bit different (4 and 5) engine off, so I gave it a EGR cleaner treatment, first down the EGR pipes to soake for a moment, and the with engine at 2000 rpm into the intake.
(efter the flow sensor)

After cleaning both EGR's sound and position was the same, but still P0069.

I tok the MAP sensor off to look down the throttle body, but still as almost clean, as when I had it off some weeks ago, so I just wanted to clean the sensor before installing it again, not knowing how it should look (no hits searching for the complete Hitachi number, only use PS91) I assumed a very little hole, but turned out to be gunk, hole should be approx 2mm!

Since the P0069 always had zero rpm. indicated, it must have been missing "atmospheric pressure consistency" from this sensor causing this error, make a bit of sense.

I didn't get any photos in the hurry, but they have plenty at the Disco forum, there 2 types of sensors, I have the one with the extra little tip.

Link to Disco forum:
- Click Here -
C6Dave   
Mon Oct 21 2019, 07:05am

Joined: Oct 01 2009
Member No: #1
Location: Northumberland
Interesting, I'll have to have a look at mine to see what state it's in.
Website
cruiserphil   
Mon Oct 21 2019, 08:50am

Joined: Jan 24 2010
Member No: #38
Location: Celbridge
Hello Nikolaj,

Thanks for that post.

Best regards,

Phil C.
C6Dave   
Mon Oct 21 2019, 10:54am

Joined: Oct 01 2009
Member No: #1
Location: Northumberland
@NikolaJ yours may look different as the original part number 1920 HS was replaced by 1920 RK - I have had mine out and cleaned it and it has the small 'nipple' extended section and it's marked: Hitachi PS91-1 6Y06
Website
Nikolaj   
Mon Oct 21 2019, 06:03pm
Joined: Aug 29 2019
Member No: #4047
Location: Roskilde
I have the one with the nipple:


C6Dave   
Mon Oct 21 2019, 06:22pm

Joined: Oct 01 2009
Member No: #1
Location: Northumberland
Interesting that they 'look' the same but have a different Hitachi part number on them. My car was built 2007 and I'm 'assuming' the sensor is original to the car but who knows. We now have 2 different numbers to search on should we ever need to replace one but I wonder all we need is the PS91 part and if the second part is actually just a date or manufacture code?.

It also comes up as JAGUAR PART NUMBER C2P19377

BTW my car has done 128,500 miles (206,795 kms) and whilst the sensor was dirty and the hole virtually blocked, it cleaned up very easily as the carbon deposit was soft.
Website
Nikolaj   
Mon Oct 21 2019, 07:40pm
Joined: Aug 29 2019
Member No: #4047
Location: Roskilde
My car is built 2008, and I guess it also the original sensor, if I searched for more than "Hitachi PS91", I just got sunglasses an other irrelevant stuff.

I guess the lesson is that everything in the EGR loop gunk up over time, so regular cleaning of those parts will keep you on the road.
321dave   
Tue Oct 22 2019, 08:11am
Joined: Sep 09 2011
Member No: #614
Location: Dublin
Nikolaj wrote ...

My car is built 2008, and I guess it also the original sensor, if I searched for more than "Hitachi PS91", I just got sunglasses an other irrelevant stuff.

I guess the lesson is that everything in the EGR loop gunk up over time, so regular cleaning of those parts will keep you on the road.


I'm on my second sensor, I broke my original sensor when working on the engine and knocked
accidentally the sensor slightly on the floor. Doesn't take much to crack them and the heat probably plays it's part in making them brittle over the years.

My cracked sensor was intially making the engine cut out! So they will interrupt the car if cracked or broken. I need to replace my spare sensor which came second hand. I think they were €68.
xantiaboy   
Sun Jan 05 2020, 08:22pm
Joined: Jul 08 2019
Member No: #3978
Location: Bracknell
I was reading this post, and decided to check the MAP sensor on my c6, as I have been experiencing rough idling on startup in cold weather. The car is a 2007 2.7 diesel and has covered 140,000 miles.

The MAP sensor was very dirty, and the housing also looks very dirty if you look into it from the MAP sensor port. Is the housing difficult to clean? Or can it be left as it is? Are there any downstream effects?

Thanks.

Here are some before and after pictures.













Nikolaj   
Sun Jan 05 2020, 09:39pm
Joined: Aug 29 2019
Member No: #4047
Location: Roskilde
That looks totally blocked, strange you didn't get P0069.
I don't think you have to clean the throttle body right away, but maybe at next given chance, when you take it off for other reasons.

There will of course also be some gunk in the inlet manifolds, but not much in mine actually, so maybe most gunk stays in the throttle body.

If theres much gunk in the inlet, I would loosen as much as possible and vacume clean it out, theres good access when the throttle body is taken out.

To get the throttle body out, tilt it 45 deg. up, still attached to the 2 inlet manifolds, then push the throttle body further into the front inlet, just enough to get it free of the rear inlet manifold.

Took me a while to get the right meaning out of the instruction found elswhere on this forum.

xantiaboy   
Tue Jan 07 2020, 08:14pm
Joined: Jul 08 2019
Member No: #3978
Location: Bracknell
Hi Nikolaj,

Thanks for the information.

There is a lot of gunk build up around the sensor port, and I think some must have dropped into the housing when I removed the sensor.

Is there access via the left hand end of the housing to do some cleaning? I don't know but it looks like the left hand vertical end separates from the main horizontal body?

Any advice would be useful.

Thanks.





David Hallworth   
Wed Jan 08 2020, 11:01am

Joined: Apr 16 2010
Member No: #90
Location: Glasgow
That big spring clip pulls off and the end pipe will detach. You can remove the entire black housing. Remove the EGR pipes, a couple of electrical connections and the fuel pipes out of the way and you can lift it out to clean it.

Mine is off the car at the moment whilst I'm doing the timing belt. I'm going to give everything a good clean whilst it's off the car.
Nikolaj   
Wed Jan 08 2020, 03:19pm
Joined: Aug 29 2019
Member No: #4047
Location: Roskilde
My advice to remove the throttle body, is what you do after doing what David just mentioned above.
CorneSoutAfrica   
Wed Jan 08 2020, 11:49pm
Joined: Oct 23 2016
Member No: #2836
Location: lichtenburg
Hi guys.
Just for some more info.

I took the plunge and removed both intake manifold/tappet covers and it was a tonne of work as you need to remove the injectors as well. My intake was gunked up and took a considerable amount of time and patience to clean it.

After that I blanked the EGR. I won’t say the car gained power but the turbos do spool up quicker and the fact that I know the intake system is clean makes my worries less. I did the cambelt water pump and diesel pump belt while I was there.

I am now wondering if removing and cleaning the intercooler may not be worthwhile. Noticed a light coating of oil in the boost pipe leading to the engine intake. Guess after 100k miles there may be some.

Strange though that the pipes leading from the turbos to the intercooler aren’t very oily. So I guess it is an accumulation of oil over the years.

I am wondering if the oilishness of the intercooler ends up working its way into the engine and that with the EGR gasses creates the tar like substance which gunks up the intake even more?

As I said. Just something I am wondering about.
David Hallworth   
Thu Jan 09 2020, 10:57am

Joined: Apr 16 2010
Member No: #90
Location: Glasgow
Be careful with the plastic covers! On the V6 Diesel Jaguars they are prone to cracking and are a hell of a price to replace!

I wondered about removing them on my car to keep my OCD at bay but decided against it as I couldn't be bothered removing the injectors.

David.
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