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Discussion Starter · #1 ·
Hi guys,

did anyone had this crack twice?! I had the renewal last year. August 2020. Today on the autobahn at 200 km/h the LH manifold cracked again. A really big crack. I was wondering, I had no RP on the display. Only after 4 km at 30 km/h on the breakdown lane, RP showed up.
I had a break down 2 weeks ago with a defective intercooler. Is the cracked manifold somehow linked to that?
I read hamed's thread about the possible reason for cracked manifolds. I will now change the MAP too.

Is the second fail of the manifold caused by a material defect or more likely by a higher pressure? Any recomendation?
Maybe the spare part was of bad quality? I bought these parts -> Link
Does anybody have experience with parts from this company?

Motor vehicle Hood Vehicle Car Automotive design


Dirk
 

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That must be a defective part for it to crack like that? Though I expect you'll have very little luck trying to get the original supplier to accept it as a manufacturing fault and send a replacement.
 

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Discussion Starter · #3 ·
I will do :) . I hope the supplier will answer by tomorrow evening.
 

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Discussion Starter · #5 ·
As Hamed wrote in his thread : Possible reason for cracked inlet manifold | Jaguar Forum (jaginfo.org)
it might be a faulty MAP in my case.
I need some assistance for my recordings. I recorded the PCM (Power Train Module) via my iCarSoft tool. Just befor the crack happend today. It is not as detailed as a recording via SDD.
I attached a combined data set.
My questions are:
  • Is the <Air flow rate from mass air flow sensor - BANK 1> really the one for the small VTG?
  • Why do I have a bigger MAF value on Bank 2 during cruising with 31 km/h? The values at 185 km/h are as expected (1 g/s + 59 g/s). The MAF are only 1 year old and should work properly.
  • Is the <Boost absolute pressure - Raw value ----- 181.69kPa> the value of the MAP sensor we are talking about?
  • How is this value been calculated? <Corrected intake manifold absolute pressure ----- 244kPa>. Why is it higher than the value of the sensor?
  • Where can you find this sensor <Manifold absolute pressure-BANK 1 ----- 260kPa> ? I thought there is only one MAP?
Maybe you can have a look at the recordings and find some interesting defects :)

Last year I checked and cleaned the MAP. It didn't look very bad.

Dirk
 

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MY 2012 XF S Portfolio Ultimate Black
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As Hamed wrote in his thread : Possible reason for cracked inlet manifold | Jaguar Forum (jaginfo.org)
it might be a faulty MAP in my case.
I need some assistance for my recordings. I recorded the PCM (Power Train Module) via my iCarSoft tool. Just befor the crack happend today. It is not as detailed as a recording via SDD.
I attached a combined data set.
My questions are:
  • Is the <Air flow rate from mass air flow sensor - BANK 1> really the one for the small VTG?
  • Why do I have a bigger MAF value on Bank 2 during cruising with 31 km/h? The values at 185 km/h are as expected (1 g/s + 59 g/s). The MAF are only 1 year old and should work properly.
  • Is the <Boost absolute pressure - Raw value ----- 181.69kPa> the value of the MAP sensor we are talking about?
  • How is this value been calculated? <Corrected intake manifold absolute pressure ----- 244kPa>. Why is it higher than the value of the sensor?
  • Where can you find this sensor <Manifold absolute pressure-BANK 1 ----- 260kPa> ? I thought there is only one MAP?
Maybe you can have a look at the recordings and find some interesting defects :)

Last year I checked and cleaned the MAP. It didn't look very bad.

Dirk
Sorry to hear this. What was the problem with intercooler? And did you hear it pop when happened?

Aa you know, the cracks due to fatigue are not at that spot. It looks more like a manufacturing defect.
The diagnosis data all look right except one thing. The 185kph one shows MAF of Bank1 is ~0 at 3000rpm. Secondary turbo should be in the loop above 2800rpm.
MAP reading looks ok but it’s not the only thing to check. Sometimes like mine, it was a bit laggy as well compared to knew one.

my answer to your questions:
  • Is the <Air flow rate from mass air flow sensor - BANK 1> really the one for the small VTG?
    No, Bank 1 is RH/ secondary turbo that is closed before 2800rpm and should read 0g/s.
  • Why do I have a bigger MAF value on Bank 2 during cruising with 31 km/h? The values at 185 km/h are as expected (1 g/s + 59 g/s). The MAF are only 1 year old and should work properly.
    bank 2 should be always higher until secondary turbo kick in. After that it depends on many things but my test shows there should be roughly similar under acceleration. The sum should be double that. ~300g/s. The figures for 185kph don’t make sense. Sum of bank 1 and 2 is 60g/s while the figure at the end of frame is 190g/s. Later is more realistic if at the time that frame was recorded you took foot off the pedal and second turbo was closes.
  • Is the <Boost absolute pressure - Raw value ----- 181.69kPa> the value of the MAP sensor we are talking about?
  • I guess you have used an OBD2 reader for these? Anything but SDD cannot read them properly. There is one byte dedicated to boost pressure over OBD2. Hence you read 255kpa ans you see desired is 267kpa. The boost pressure (manifo is above 255but obd2 cannot see it.
    boost pressure is pressure sensor at the output from secondary turbo. Again 189kpa doesn’t make sense. Under than load it should be 260.

  • How is this value been calculated? <Corrected intake manifold absolute pressure ----- 244kPa>. Why is it higher than the value of the sensor?
  • It is calculated by your software based on wrong 255kpa value. Ignore it.
  • Where can you find this sensor <Manifold absolute pressure-BANK 1 ----- 260kPa> ? I thought there is only one MAP?
  • Manifold absolute pressure-BANK 1 is the one from MAP sensor on top of throttle body. The past point before getting into cylinders and important one
    Boost pressure in diagnosis software glossary is the pressure at the output of secondary turbo. It is from an identical pressure sensor installed just under hydraulic steering pump and connected to secondary turbo by a pipe. Everywhere else on the net, boost pressure and manifold absolute pressure are used interchangeably.
    when MAF for bank 1 is 0, boost pressure (secondary turbo pressure) also should be 60-97kpa.
    MAF reading for a cold engine should be below 97kpa. More like 40-80kpa.
    something is wrong.one of these:
  • - the diagnosis device is wrong.
  • -MAF sensor for RH turbo is reading 0 regardless
  • Turbo Bypass valve meaning the VGT pressure is somehow leaking into secondary turbo that shouldn’t happen.
  • -Secondary turbo shutoff valve. meaning secondary turbo is in the loop all the time. Again why MAF reading is 0?
  • Vacuum line that operates actuators.
There is a routine in SDD to recalibrate air path actuators. Maybe that’s what you needed. Specially the VGT arm and turbo bypass valve are passive.

Another FM managed to weld the intake manifold. Since this crack is very accessible, you might be able to get away with it.
 

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Discussion Starter · #7 ·
Thank you hamed. I will have to review your data in detail later this day. Very helpful for my further analysis.
Yes I saw the thread dealing with the welding repair of the manifold. My crack is bigger as you can see. The crack is running around the edge towards the driver. You can lift a bigger part of. So I think it is too big for welding it assembled.

Your are right, I heard big plop when the intercooler gave up. I didn't see the cracked bad part. But at the time it blew off, I could hear a sound like a bigger air leakage. And the oily air
could be found around the intercooler. The garage assembled a spare part from Mahle. After that the cooling fan was working right (as expected :) ) for the first time since we bought this car. This fan never ran after ignition off before. Now it does according to the ambient condition.

The supplier of my manifold parts already replied. They are sorry. Seems to be a material defect. But the warranty time is over . 1 month too late. No I am heading for the orignal FoMoCo-parts from LR. This time I would only change the cracked side (LH). I hope the other side does not have this material defect. I will have to spent 600 EUR for the working hours of my mechanic again. I don't want to do this every year. And I don't have a garage with space enough for a DIY repair session. So I maybe it's better to buy the original parts.
 

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Discussion Starter · #8 ·
Thank you hamed for the detailed answers. You are right, it is normal OBD2 Scanner (Link). And I think it is the way wrote. The data of the frames are recorded not at once but at different seconds. So it might happen that the MAF data is taken at time x and the Manifold absolute pressure is taken at x+10 seconds. So my data is not as reliable as I thought.

Now the next step will be for my mechanic. Change the manifold and check the whole turbo-path for loosen clips, broken hoses or damaged wires. After that I will start a longer SDD session to gain knowledge and collect data. Will be interesting. Looking forward to. I will start with this service procedure you mentioned to recalibrate the air path. That hasn't been carried out after both MAFs have been changed. Maybe then my new MAP sensor from Triscan will work without RP.
Anyway I hope to record more reliable data with SDD.

Question to everybody: Would you change both manifolds? The cracked and the good one? Or would you only change the cracked one?
Why did, in my case, only crack the left manifold twice? Is this somehow linked to any geometric reason? Or something else?

Have a nice evening
Dirk
 

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Thank you hamed for the detailed answers. You are right, it is normal OBD2 Scanner (Link). And I think it is the way wrote. The data of the frames are recorded not at once but at different seconds. So it might happen that the MAF data is taken at time x and the Manifold absolute pressure is taken at x+10 seconds. So my data is not as reliable as I thought.

Now the next step will be for my mechanic. Change the manifold and check the whole turbo-path for loosen clips, broken hoses or damaged wires. After that I will start a longer SDD session to gain knowledge and collect data. Will be interesting. Looking forward to. I will start with this service procedure you mentioned to recalibrate the air path. That hasn't been carried out after both MAFs have been changed. Maybe then my new MAP sensor from Triscan will work without RP.
Anyway I hope to record more reliable data with SDD.

Question to everybody: Would you change both manifolds? The cracked and the good one? Or would you only change the cracked one?
Why did, in my case, only crack the left manifold twice? Is this somehow linked to any geometric reason? Or something else?

Have a nice evening
Dirk
If the intercooler also blew, there should be excessive pressure in system that could have two reason in opinion:
wrong reading from sensor or boost leak fooling MAP reading in a fracture of second due to complex dynamics.
the boost control system has only one feedback and that is MAP. The rest are local feedbacks and have no control over boost pressure.
 

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Discussion Starter · #10 ·
good news :) Thank's hamed.
If I got you right, I should focus on the second turbo path. The VGT path should only fail due to a defective turbo bypass valve. I don't have a drawing like the one from OBC John with all the turbo paths and sensors. That would be helpful to find the root cause for my "over pressure". It would even help me to understand what sensors I have to check and how this system works. Could anyone share such a drawing? Or tell me where to get one?

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Discussion Starter · #12 ·
First I have to buy a WM :) I think now it is time :)
 

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First I have to buy a WM :) I think now it is time :)
 

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Discussion Starter · #14 ·
I received the cover today. Very fast. Ordered Tuesday 2 PM. Received 24 hours later. Ordered at Herman Jag shop in Germany. Cover was on stock. If a dealer has such a part on stock, they should fail more often as Jaguar is admitting :). The original FoMoCo part is slightly different to the China part that cracked again. The China part is more shiny than the FoMoCo part. One reason for that is the surface of the mold. Another is the material. Another is the temperature during the injection molding process. Another is the releasing agent..... and some additional.... It is not the main indicator for poor quality. I will send some pictures later on. If you touch both parts, the FoMoCo part seems to be more robust.
Since I couldn't find pictures from the China part with the PA material stamp, I can't tell if it is the same material. The FoMoCo part is the same as my orignal one PA6 GF35. I read in another thread it might be a PA6.6 GF35%. It is a PA6. Slightly other specifiaction and intended use. I thought Jaguar would change the part to PA6 GF40 or GF45 after the first cracks. But they did't.
Now the cover will be assembled. Water pump should be changed, too. If available. Whole motor service with new filter and oil. New airfilter. Tightness and maybe smoke test will be carried out by the mechanic. He will also check the MAF and MAP with his Gutmann system. Hopefully I will get the Cat back on Friday. So I have the weekend for SDD sessions. I thought my old Audi A4 2.5 V6 diesel was a nice and expensive hobby :) .
 

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Discussion Starter · #15 ·
Thanks Hamed. I downloaded the manual yesterday. But couldnt find the overview drawing. For the beginning the PDF should be sufficient enough. Do you use another/additional manual?
 

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Hi guys,

did anyone had this crack twice?! I had the renewal last year. August 2020. Today on the autobahn at 200 km/h the LH manifold cracked again. A really big crack. I was wondering, I had no RP on the display. Only after 4 km at 30 km/h on the breakdown lane, RP showed up.
I had a break down 2 weeks ago with a defective intercooler. Is the cracked manifold somehow linked to that?
I read hamed's thread about the possible reason for cracked manifolds. I will now change the MAP too.

Is the second fail of the manifold caused by a material defect or more likely by a higher pressure? Any recomendation?
Maybe the spare part was of bad quality? I bought these parts -> Link
Does anybody have experience with parts from this company?

View attachment 188205

Dirk
Dirk the inlet LH & RH manifolds tendency to crack is a well known problem. The reason they crack is due to the fact they’re plastic & bolted onto an Aluminium cover. Over time due to difference in expansion/ contraction of material & heating/cooling a crack or cracks will form. Once cracked if the MAP sensor is operating with correct output signals at design pressure limits your RP warning light will light up due to the reduced pressure in the air intake manifold. If your RP didn’t function it’s probably due to a faulty MAP sensor. When they crack you can hear an audible increase engine noise. The replacement manifolds you purchased were probably not original Jaguar intake manifolds but cheap copies made in China, if Jaguar manifolds are susceptible to cracking imagine cheap Chinese ones are even more likely to crack. In UK new OEM manifolds cost £800 each but Chinese copies £100 each. To prevent cracking let the engine warm up before booting it or engaging sports mode which allows higher revs between gear shifts & higher intake turbo boost pressures. For what they cost it’s worth changing the MAP & MAF sensors at 70k miles.
 

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Discussion Starter · #17 ·
Thanks CJH for your comments. I hope the manifolds does not really cost 800 £ each. If you buy an orignal one on your own from a dealer, they cost about 320 EUR (274 £) each. Manucturing costs (injection + friction welding) of such big part made of PA6 GR35 should be around 15 EUR in CZ + sealing + screws +... Finally it should be sold around 35 EUR by the manufacturer itself to Jaguar. Best guess :)
The chinese parts are not alwas cheap copies. My company also started to buy some of our components in China. And today most of the parts are really much better than the European source. But they cost nearly the same as the European source. So they are no longer cheap but better quality for the same price. Due to Corona we changed some sources back to Germany and developed the skills of our new suppliers. And it works.
You are rigtht comparing the price of MAP+MAF to the price of a cracked manifold and the working hours. But wouldn't it be better, if the Jag software would monitor the plausibility of the sensor signals? Ok :) Dream on :) as Aerosmith would say... We are working on the same thing with our products. Preventive maintenance based on sensor signals...

Back to the problem :)
In my case a defective MAF sensor was the root cause. My mechanic told me that he retrieved values of 900 g/s and a desired boost pressure of 500 kpa. He swapped the two MAFs and the bad values changed from the second turbo to the first (VTG). Now everything is fine again. No visible damages at the second manifold or the intercooler. No hoses or clips were loose. I will check the sonsor signals of MAP + MAF tomorrow and try to calibrate this air path. And of course assemble the bad MAF to check what "bad" means :) . I will report.

By the way, does anybody know the max boost pressure that the big turbo (not the VTG) can deliver?

Dirk
 

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Discussion Starter · #19 ·
I didn't check the dimensions :) . I just meant the second turbo for the boost pressure at 2.800 rpm and above. For me it is a little bit confusing with turbo 1 or 2 or bank 1 or 2. I think, Jaguar numbered these parts considering the drivers seat on the UK (right) side. So it is bank 1 (boost turbo) and bank 2 (vtg turbo). But from the view of the inteded use, it is turbo 1 (vtg, bank 2) because it is the first turbo that will be used and only after that, turbo 2 (boost turbo) kicks in. Boost turbo = higher pressure = big turbo. Maybe that was my fault and is a little bit confusing ;-).
 

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There's a quite comprehensive description of how the twin turbo system works in the workshop manual from page 1759, it was @hamedhbb that recently posted the find in the manual.
 
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