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safarimechanic

Member Since: 19 Nov 2020
Location: Orlando
Posts: 1

Puma Knocking Noise

Hey all,

In the process of putting together a Puma 2.4 110 at my shop. We were at the end of the build, everything running smooth. About 200 miles into break in/test driving the vehicle, right after filling up the tank, the vehicle lost power for a few seconds, and developed a significant knocking sound, seemingly localized around cyl#2. The sound is hard to place whether it's top end or bottom end, but it's definitely centered around #2. A small amount of diesel was noted around the #1 and #2 injector valve cover entries, which was corrected with new copper seals. No abnormal codes were noted in Autologic, all seems to be fine on the ECM side.

First step was confirming correct injector coding in Autologic, followed by a pump calibration and injector pilot correction learn. Condition remained. Next, to rule out a faulty injector, the injectors were moved around the engine, recoded, and ran again to see if the sound moved at all. No luck. Suspecting possible valvetrain involvement, the valve cover was removed, free movement of all components was confirmed and no abnormal wear was noted. Oil was drained and filter was removed and cut open. No abnormal particles in the oil or the filter save for some tiny pieces of paint marker from the Ford factory assembly procedures. Zero magnetic partcles whatsoever. Oil pan was removed, bottom end inspected, and all seems to be in order down there. No abnormal wear patterns or indication of excess play or overheat condition was noted upon visual, tactile, and endoscope inspection. Additionally, the sound doesn't change in intensity when loading the engine - which would further suggest that the problem isn't in the bottom end.

All injectors were unplugged in order to monitor engine reaction, these kill tests were followed by identical behavior, which indicates that we have equal compression and combustion across the board. A note: when Injector #2 is unplugged, the knocking sound all but disappears.1, 3 and 4 don't do anything to the sound.

Before anyone directs me to search the forum or links me to other threads, I've probably read them - I've read everything possible regarding this condition on this engine and am aware of SSM38792 and the oil squirter issues and am fairly confident that condition isn't the issue at this time. Apart from the godawful sound, the vehicle runs phenomenally, and no abnormal behavior has been noted since the momentary loss of power. Fuel pressure dynamics in the Autologic indicate that the pump, rail, and associated regulation are doing exactly what they're supposed to. The injectors have been all but ruled out by moving them around to different positions. Physical wiring faults to the injectors would likely trigger a DTC in Autologic, and this hasn't occurred.

My next move, at this point, is to reflash the ECU, recode the injectors, relearn the pump and injectors and start from scratch. The only other possibility, mechanically speaking, could be a clogged oil passage to a #2 hydraulic tappet unit or to an oil squirter - the oil squirter scenario would have likely made metal which hasn't been noted at this time.

Hoping that there is some sort of Puma expert on here who could point us to an "A-ha!" or a lightbulb moment regarding this condition. There is a dearth of knowledge on these motors in my country, and you lot seem to know the most, so hopefully this admittedly long-winded writeup yields fruit of some sort.

Thanks in advance!

4th Dec 2020 1:45pm

Dinnu

Member Since: 24 Dec 2019
Location: Lija
Posts: 3414

2012 Defender 90 Puma 2.2 CSW Santorini Black

You do not mention what kind of work was done to the engine, if at all.
I am no expert on the 2.4s, but could have something fell into the intake, somehow went past the turbo compressor without damaging it, but damaged a valve? Maybe remove the injectors again, turn the engine over to top dead center for each piston just before the power stroke, and do a leak down test? 1988 90 Hard Top, 19J Diesel Turbo, Shire Blue - Restoration ongoing
2012 90 CSW, 2.2TDCI, Santorini Black

4th Dec 2020 7:45pm

GREENI

Member Since: 22 Aug 2010
Location: staffs
Posts: 10382

Take it out, whack in an LS...

Click image to enlarge

4th Dec 2020 7:48pm

mwestcrew

Member Since: 09 Dec 2019
Location: South Warwickshire
Posts: 251

2011 Defender 130 Puma 2.4 HCPU Baltic Blue

Just to confirm....injectors on this engine can make a knocking type sound, two of mine have done it at different times. However a primary learn has almost eliminated it each time.

It’s interesting that the kill test on No.2 considerably reduces the knock. It could be small end, when no fuel is present and consequently no combustion, no instantaneous load. Just a thought....... 2011 130 Utility Body
2005 110 Van

4th Dec 2020 11:48pm

Fernando

Member Since: 25 Oct 2017
Location: CABA
Posts: 92

2008 Defender 110 Puma 2.4 SW Bonatti Grey

Loose injector, change the copper washers and the screws that hold it!
I think the tightening torque is 6NM and then 180º

5th Dec 2020 1:00am

Safarihp

Member Since: 14 Feb 2014
Location: Oraldno
Posts: 15

1985 Defender 110 200 Tdi USW Barolo Black

Thanks for the responses.

This is a new genuine engine. We are now US experts on the Puma or so it seems.

We are Very good at installing LS3s wish we could on this truck.

https://safarihp.com/project-johnson-defender-110/

We have checked the injectors many times over. New washers and learns each time.

We have been running circles on the truck and the knock for sure.

Thanks for any advice and please keep any suggestions coming. We really feel that it is fuel related as there is zero metallic particles in the oil x 2 drains.

We have also moved the valve train from a runner and installed on the offending motor without any change.

Thanks for reading and offering us Yanks a few suggestions.

7th Dec 2020 4:31pm

Bluericky

Member Since: 26 Jun 2014
Location: Cornwall
Posts: 647

2009 Defender 110 Puma 2.4 DCPU Keswick Green

Some great builds and conversions in your portfolio !

I can’t help much with your knocking but if it is as you suspect fuel related , have you looked at changing the suction control valve or fuel rail sensor ?

I don’t believe either would show with a diagnostic scan . Both are known to cause all sorts of issues. If you do replace , only use genuine parts . The others aren’t worth the hassle .

Good luck https://www.instagram.com/hustynminepark/

7th Dec 2020 11:01pm

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