Grand Cherokee WJ 2.7crd Injector No5 seal fail - help ?
Discussion
So, I'm finally suffering my first injector seal fail after over 10 years of owning 2 WJ 2.7s !
There's so much experience out there now on the now, so hopefully someone here has done this. I have a couple of questions before I even start.
1) The bolt and seal kits, they start at under £20 of eBay for unbranded stuff, are they ok or should I seek a OEM part from a Mercedes parts shop?
2) Cut a square panel, or cut circular holes in the scuttle panel. Is there a preferred option? Id have thought the square panel gives more working room.
3) Should you replace the metal after the job is done, or will rain water poor into the engine compartment ?
Cheers
There's so much experience out there now on the now, so hopefully someone here has done this. I have a couple of questions before I even start.
1) The bolt and seal kits, they start at under £20 of eBay for unbranded stuff, are they ok or should I seek a OEM part from a Mercedes parts shop?
2) Cut a square panel, or cut circular holes in the scuttle panel. Is there a preferred option? Id have thought the square panel gives more working room.
3) Should you replace the metal after the job is done, or will rain water poor into the engine compartment ?
Cheers
Done it (injector seals) yes, number 5 or 4 for that matter, no.
Number 4 started letting go on mine just as I part exchanged it and the garage didn't care as they just put it up on ebay.
So, from memory .
When the engine is cold, clear away as much of the black residue as you can (assuming you have this).
Whilst cold, it will chip away fairly easily.
Second, familiarise yourself with what you will need to do to remove the injector as you will need to be moving fast for the next bit.
Set out all the tools you will need and try to temporarily disconnect the plug if possible so you don't rush that and break it (then put it back on).
Take it out for a good hard run, you want the engine block to be as hot as possible.
Once hot, the black residue softens - but not for long!
When back home, working fast, disconnect the plug and the fuel line.
What I used to then do, is to slacken the bolt 3-4 turns and then blip the engine. I can t recall what I did to stop the engine from starting other than being quick with the key, but you don't want it to start, you're just using the compression to start the injector moving out.
DO NOT fully remove the bolt for the above process unless you want to launch the injector!
You should then be able to wiggle out the injector after fully removing the bolt and hold down clamp.
You need to be quick with the above, as the engine cools, the black residue will harden again quite quickly and then you'll have real issues with disassembly.
Once out, you will need to clean everything down.
An injector seat cutting tool will be required for the seal area.
A spare bolt (you can use the old one) can have a slot cut down the length of the thread, you can then use this to clean out the thread in the head.
Do not reuse the bolt as they are stretch bolts.
Once all cleaned up (including the injector), you just need to reassemble - easy when it's all clean.
I can't recall the torque setting for the bolt, but it was torque up, and then turn a further 90 degrees, pause and then a further 90 degrees.
It was originally only the first 90 degrees, but I understand Jeep later required the second turn due to recurring issues.
Once all connected back up, a vacuum pump can be used to prime the diesel lines. A clear piece of plastic tube with a 'V' cut into the end can be inserted into the bleed point. You need the 'V' so the points push the sealing ball in whilst the mouth of the 'V' allows the air/fuel to flow.
Once all the air is removed you're good to go.
Don t skimp on the air bleeding though as the high pressure pump needs the fuel to act as a lubricant, any air in there will knacker it quickly.
As for the hole, circular seems the way to go, with a large rubber grommet to fill it afterwards.
I'm not home until Friday and can have a look over the weekend as I may have spare bolts and seals still which I can post to you.
Number 4 started letting go on mine just as I part exchanged it and the garage didn't care as they just put it up on ebay.
So, from memory .
When the engine is cold, clear away as much of the black residue as you can (assuming you have this).
Whilst cold, it will chip away fairly easily.
Second, familiarise yourself with what you will need to do to remove the injector as you will need to be moving fast for the next bit.
Set out all the tools you will need and try to temporarily disconnect the plug if possible so you don't rush that and break it (then put it back on).
Take it out for a good hard run, you want the engine block to be as hot as possible.
Once hot, the black residue softens - but not for long!
When back home, working fast, disconnect the plug and the fuel line.
What I used to then do, is to slacken the bolt 3-4 turns and then blip the engine. I can t recall what I did to stop the engine from starting other than being quick with the key, but you don't want it to start, you're just using the compression to start the injector moving out.
DO NOT fully remove the bolt for the above process unless you want to launch the injector!
You should then be able to wiggle out the injector after fully removing the bolt and hold down clamp.
You need to be quick with the above, as the engine cools, the black residue will harden again quite quickly and then you'll have real issues with disassembly.
Once out, you will need to clean everything down.
An injector seat cutting tool will be required for the seal area.
A spare bolt (you can use the old one) can have a slot cut down the length of the thread, you can then use this to clean out the thread in the head.
Do not reuse the bolt as they are stretch bolts.
Once all cleaned up (including the injector), you just need to reassemble - easy when it's all clean.
I can't recall the torque setting for the bolt, but it was torque up, and then turn a further 90 degrees, pause and then a further 90 degrees.
It was originally only the first 90 degrees, but I understand Jeep later required the second turn due to recurring issues.
Once all connected back up, a vacuum pump can be used to prime the diesel lines. A clear piece of plastic tube with a 'V' cut into the end can be inserted into the bleed point. You need the 'V' so the points push the sealing ball in whilst the mouth of the 'V' allows the air/fuel to flow.
Once all the air is removed you're good to go.
Don t skimp on the air bleeding though as the high pressure pump needs the fuel to act as a lubricant, any air in there will knacker it quickly.
As for the hole, circular seems the way to go, with a large rubber grommet to fill it afterwards.
I'm not home until Friday and can have a look over the weekend as I may have spare bolts and seals still which I can post to you.
Edited by Ledaig on Thursday 18th June 00:01
Task completed, and so far seems to be working ok.
Notes to help anyone else.....
Cut the big square hole in the scuttle tray above, approx. 5.5 x 7 inches
No5 is a pig to reach, I'm over 6 foot and still had to stand on a tool box to help reach over.
Getting engine hot, using compression and twisting the injector helped get it to pop out. Put a 13mm deep socket over the fuel intake connector and you can twist it side to side to help loosen up.
I spent an hour cleaning up the gunk, it was worse than I thought because it had collected mostly behind the injector out of sight.
Use a 19x17mm seat cutting tool to clean of the face. Reaching over its hard to exert much downward pressure, so this takes a bit of time. Put grease on cutting face to collect any shavings.
Stretching over the engine and looking down, I could only see half the seat face (which seemed good), I tried taking pictures but the camera wouldn't focus properly. I'm hoping I've cleaned the face good enough, time will tell.
Genuine bolt and washer was like £3 from my local official MB dealer parts department.
I used Febi injector grease, expensive at £15 for a small tub. But you've come this far so do a proper job hey ?
Using the old bolt with groves cut along the threads, I must have run that in and out the bolt thread 30 times to fully clean the threads out.
A hoover with a 6mm plastic tubing taped in the end will suck the crap out the hole as you clean too.
I used a metal scribe to "tap" the bottom of the thread hole to make sure I was all the way to the bottom.
I used the 7mN (Christ, that's like nothing in torque. Lucky I've got a Snap-On torque wrench that reads that low)) plus 90 degree's, wait a moment plus 90 degree's method.
Reassemble, bleed the fuel lines. Took several turns till it fired up.
All seems good for now.
Time, well I'm a home mechanic working on my driveway, never done this before, cutting the hole, doing the fix, cleaning the black death up, putting it back and remaking a metal plate for the scuttle I'll book 12 hours.
I guess a pro mechanic, who's done this before, with a garage of all the good tools would do it in half the time.
In fairness, I do stop for lots of tea
If number 4 goes next, I'm sure I'll do it a lot quicker too
Notes to help anyone else.....
Cut the big square hole in the scuttle tray above, approx. 5.5 x 7 inches
No5 is a pig to reach, I'm over 6 foot and still had to stand on a tool box to help reach over.
Getting engine hot, using compression and twisting the injector helped get it to pop out. Put a 13mm deep socket over the fuel intake connector and you can twist it side to side to help loosen up.
I spent an hour cleaning up the gunk, it was worse than I thought because it had collected mostly behind the injector out of sight.
Use a 19x17mm seat cutting tool to clean of the face. Reaching over its hard to exert much downward pressure, so this takes a bit of time. Put grease on cutting face to collect any shavings.
Stretching over the engine and looking down, I could only see half the seat face (which seemed good), I tried taking pictures but the camera wouldn't focus properly. I'm hoping I've cleaned the face good enough, time will tell.
Genuine bolt and washer was like £3 from my local official MB dealer parts department.
I used Febi injector grease, expensive at £15 for a small tub. But you've come this far so do a proper job hey ?
Using the old bolt with groves cut along the threads, I must have run that in and out the bolt thread 30 times to fully clean the threads out.
A hoover with a 6mm plastic tubing taped in the end will suck the crap out the hole as you clean too.
I used a metal scribe to "tap" the bottom of the thread hole to make sure I was all the way to the bottom.
I used the 7mN (Christ, that's like nothing in torque. Lucky I've got a Snap-On torque wrench that reads that low)) plus 90 degree's, wait a moment plus 90 degree's method.
Reassemble, bleed the fuel lines. Took several turns till it fired up.
All seems good for now.
Time, well I'm a home mechanic working on my driveway, never done this before, cutting the hole, doing the fix, cleaning the black death up, putting it back and remaking a metal plate for the scuttle I'll book 12 hours.
I guess a pro mechanic, who's done this before, with a garage of all the good tools would do it in half the time.
In fairness, I do stop for lots of tea
If number 4 goes next, I'm sure I'll do it a lot quicker too
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