It’s been all over the news and the internet as well as gossip on the streets, the problems with the Nissan Navara D22 engine ‘destroying itself’. So, once and for all a true summary of the problem and the solution to make sure you don’t fall victim to this.
This includes Chris Vince’s info on what the problem is, why it happens and what can be done to sort it.
Also included are sources for parts needed and associated part numbers.
Finally a brief decription of work invloved to replace bolts, bearings and oil seal
More detailed information can be found by reading the full thread:-
Also the sticky big end bearing change:-
Assuming you are in the EU and your engine number is before YD25DDT1219661 in your log book or found above the alternator on the block, then it is at risk – d22’s with yd25 2.5 tdi engine (2002-2005), especially around the 60,000mile mark. However it can happen at any mileage and regardless of full service history, so if you have a D22 of this age it is HIGHLY RECOMMENDED that this work is undertaken.
If you look at the engine number on a machined part of the block approx 50mm x 30mm immediately behind the alternator it will be stamped YD25 plus your engine number.
The fundamental fault lies with con rod bolts that are NOT up to the job.
I think that the bolts are permanently damaged during the angle torquing phase of their installation, also the lack of quality of these bolts means that they pass through their elastic limits (meaning that when undone they should return to their exact original size, specification and condition) into their plastic limits (meaning that permanent changes to their dimensions has occurred (due to being overstretched), and to their molecular makeup (causing graining to take place, a form of work-hardening, leading to a critical catastrophic failure or snapping after further use).
More worrying, all of the shells fitted to the rods have ‚Äòpicked up‚Äô on the bearing surfaces whilst those in the end caps look OK apart from the fact that there is a distinct lack of a wear surface across the entire shell, the only visible indicators being in the middle of the shells other unfortunate owners suffering the same catastrophic failures they do not mention a long term knocking that was getting worse with age (indicating a slow wear rate taking place), many just state that the car was driving perfectly normally, when a loud knocking was heard (I believe this to be the first bolt snapping allowing the endcap to open up) this was then closely followed by the terminal failure of a rod coming through the block (second bolt snapping)!
My only explanation for this is the failure of the securing method i.e. the end cap bolts, even if there was wear in the big ends past the accepted limits causing the characteristic big end knocking to be heard, the end cap bolts should have easily coped with this and held the parts together!
I am sure most of us will have heard an engine with severely worn big end bearings, I have heard numerous and yet none of these engines threw their rods through the blocks!!
A rod through the side of any engine must mean that it has become disconnected from the crankshaft journal the only way this can occur is for the bolts to come undone or snap, especially so considering the reports from owners when the failure happened.
I am also starting to think that the knocking noise so many of you have written about on morning start up is the first warning sign you need to heed without delay!
the bearing linings were being stripped by hammering on the power stroke, the cause being oil starvation.
In the YD25DDTi engine the oil strainer pick up pipe is bolted to the rear of the sump/oil pan, oil then travels in cast galleries across the sump and along the full length of the sump back across again at the front of the engine until it comes to a flat horizontal orifice approx 15mm dia.
Into this orifice is placed a spigoted ‘O’ ring.
The sump then bolts back into place the top of this oil ring just making contact with the inlet orifice of the oil pump, there is NO physical fixing, sealant etc just dry contact, over a period of time shall we say 60-90,000 miles, and having endured numerous temperature cycles in a very hostile environment, it can be reasonably expected for the ‘O’ ring to change in shape, size and or malleability, thereby compromising the sealing effect.
If/when this occurs it could be reasonably assumed that air will be drawn into the oil pump causing cavitations thereby starving the engine of oil, instigating hammering on the bearings during the power stroke until an increasingly common catastrophic event occurs.
This ring is ALL that stops the engine oil pump from sucking air, then running the big ends dry, hammering and stripping the bearing linings eventually (in a very short time) putting a rod through the block!
if a big end bearing is so badly worn that it can no longer be ignored due to it‚Äôs knocking, the bolts should hold the rod together, and not snap, as is the case with the OE bolts:-
1. Replacing the big end bolts with items made by ARP. Bolts cost ¬£63 Nissan ones approx ¬£46
2. Replace the ‚ÄòO‚Äô ring, using a standard one but modify the way it is installed by: Cost ¬£1-43
a. Placing a 23mm x 1.5mm ‚ÄòO‚Äô ring inside the top recess, to increase the surface area of seal. Pence
b. Using liquid gasket on both sides of the ‚ÄòO‚Äô ring flange during installation
3. As the sump is already off, fitting a new set of upgraded bearing shells from another manufacturer
Nissan have postioned 2 x 6mm bolts directly behind the flywheel, so the engine/gearbox DO need to be seperated to remove the sump.
both units can remain in the vehicle, you only need enough room for a 1/4 drive socket extension
ARP bolts from co ordsport.part no 202-6005 ¬£43.97.tel 01384216102.
The parts to modify the troubled engines cost around ¬£150 and the engine stays in place. The job takes around 20 hours by the DIY mechanic working of axel stands but if they had a garage vehicle ramp/lift could be done in 10 hours.
Bolts: Nissan SR20 Rod Bolt Set Part no ARP 202-6005 = ¬£64.02 + carriage
Hinckley Fields Industrial Estate
Tel: 01455 234200
Big end bearings: ACL 4B2626 (no filing req‚Äôd) or 4B2751 (filing req‚Äôd). Size of bearing Standard if crankshaft not damaged = ¬£26.06 + carriage, in their Duraglide material (this is lead/copper).
ACL also do an Aluglide range which is aluminium/tin overlay, is to be avoided in a D22.
Engine Parts (UK) LTD
Unit 17, Thurrock Commercial Park
Purfleet Industrial Park
Tel: 01708 890494
Oil seal: Nissan part no N15066VK500 = ¬£1.91
You will also need a new oil strainer to sump gasket Nissan only part No. 15053-1E400 approx ¬£2-00.
bearings– ACL 4b2751 (std) from andy at engine products bradford (01535 272271) or from ACL usa (616 956 1300 ext 107 (micheal flynn)) about ¬£40 inc delivery.
ACL uk.phone derek andrews 01708 890494
ACL4b2751 Duraglide lead/copper in std.
bolts– arp 202-6005 from pri racing (0161 718 6721) ¬£43+vat
bolts from JDM Performance ARP202-6005 ¬£43inc delivery.
oil seal– 15066-vk500 nissan main dealer. ¬£2-3
filter kit– 002042k milner off road (01629 734411) ¬£10+vat.
You can do this job with the engine in the car.
If you intend to replace the pathetic bolts it would be stupidity in the extreme not to change the big end shells, it will take approx another 1.5 hours but you would have already done the hard work getting to the crankshaft, and will rejuvinate your engine by removing the already present wear!!
I was amazed to find that the end shells on my replacement engine with just 24K miles were almost at the upper wear limit.
Front diff by removing its crossmember support (leave propshaft connected to transfer box)
Air con compressor (but just enough to tie it up do NOT touch the pipes!!)
Undo the nearside steering idler from the chassis (no need to disconnect and swivel joints, let it hang down out of the way)
Disconnect rear prop shaft joint
Undo rear gearbox mounting bolts 2off (no need the remove gear levers etc)
Undo bell housing and withdraw approx 20mm from engine (just enough to get a 1/4 drive 10mm socket to the 2 bolts)
Remove lower sump
Remove upper sump
The crankshaft and big ends will then be right in front of you, the ‘O’ ring is captive in the upper sump.
The Nissan con rod bolts are an interference fit, and need to be carefully tapped out, on each rod, after removing one replace it with a slightly loose fitting tightened nut and bolt before tapping out the other, to avoid distorting the end cap.
If you use ACL 4B2751 end shells as I did, the only mod needed is to reduce the width of the tang by approx 1.2 mm with a few stokes of an engineers file.
Basically the original slot for the tang (this stops the shell spinning in the housing) is ever so slightly too narrow for the ACL bearings.
All that is involved is, you hav to narrow the ACL tang to allow it to fit the slots inthe bearing housings this is very easily done by filing it with a small file,about half a dozen passes equally on each side.
You must remove material from both sides to keep the shells central in the housings.
The ARP bolts are just about the best available, they are truly elastic and meant to be used and removed over and over again, make sure you coat the threads with the special ARP grease (supplied in the kit) before fitting the nuts.
They recommend tightening to 40 ft/lbs releasing and retightening at least 3 times to settle them in.
Do NOT worry about how to fit them, having driven out the rubbish ones, ARP engineering and the fit is just outstanding they just pull in using the thread for the last 5mm.
You will have to use a Nissan ‘O’ ring purely because it is a spigot fit and nothing else I have found is suitable, but I modded mine to give a larger surface area and increase the crush value, by placing a 23.5mm x 1.5mm plain ‘O’ ring on either side, also, I used the same liquid gasket as is used on the sump flanges to ‘stick’ the ‘O’ ring ‘sandwich’ to both the sump housing and oil pump flange.
Parts – ¬£100 – ¬£150
Labour – Anywhere from ¬£200 to ¬£1200, depending on “mate rates” etc.
Total cost should run at max ¬£1600
Cost of replacement engine if you don’t do these mods – ¬£3-3500!
Piece of mind knowing you have done the mods – PRICELESS!
Thanks to Chris Vince, and all others who have contributed information
For more information and discussion on this you can find it all on the Navara forums at www.nissan-navara.net