M62 TU timing chains and Vanos rebuild

[gussy]

Hi All.

I’m in the middle of replacing the timing chains, guides and rebuilding the Vanos. The upper u shaped guide decided to part with its plastic.... [emoji1362]

Just got the lower cover off and there’s a lot of black gunk in there. Is this normal for a 265000 km engine? Or was it poorly serviced before I bought it I wonder?

https://uploads.tapatalk-cdn.com/20191109/4815be38a3c1ddeb5dad29819e3da6b1.jpg

[FisherX]

Maybe it's normal with an engine with that many miles on it. I've worked out that we have to use synthetic oil in our M62's. They run so hot that they would fry normal oil. I've been monitoring my engine temps and normal temps are around 115 deg C on the highway and get up to 135 around town.

I'll be looking with interest in what you are doing as I think I need to do the same with my engine.

It has a little rattle for half a second when I start it up.

[Pedro_The_Swift]

How does stuff not boil at 135?:Thump:

[gussy]

Ah yep that could make sense... I’ve only been using full synthetic but that’s no guarantee the last person didn’t! Once I’ve gotten it done I can post a list of part numbers here for you if you like fisherX.

It’s a pretty straight forward job - but there’s some major things that rave seems to skip over - like how difficult it is to get the injector electronics off - you need a pick tool(s) to remove all the metal cir clips on the connectors before removing the electronics boxes. and the crank bolt.... so tight - a one metre length of pipe over the breaker bar and you could still see it deflect.

https://uploads.tapatalk-cdn.com/20191110/e1afed0cbf36ea4885d10be5061ca271.jpg

Swapping out the Vanos seals. The ones on the left are the new ones. This was actually pretty easy if you follow the instructions on the Beisan website:

Beisan Systems - Procedures - M62TU Vanos Procedure (http://www.beisansystems.com/procedures/m62tu_vanos_procedure.htm)

[gussy]

Items needed for timing chain(s) replacement and Vanos rebuild on l322 Bmw 4.4 v8 m62tu:

upper and lower timing chain and guide kits (I used Febi Bilstein)

Timing chain kit for crankshaft febi 47500
Timing chain kit for camshaft febi 47502

eBay special Vanos rebuild kit

Extra Land Rover genuine parts so you can put it all back together:



Part Number
Product
Item Price
Quantity
Total


LR051050.L8
LR051050
AU$54.28
1
AU$54.28


LYG000120.L8
LYG000120
AU$10.69
2
AU$21.38


LUD000010.L8
LUD000010
AU$23.02
2
AU$46.04


PQS000220.L8
PQS000220
AU$39.48
1
AU$39.48


LYF000030.L8
LYF000030
AU$3.85
16
AU$61.6


LVF000040.L8
LVF000040
AU$75.47
1
AU$75.47


LYP000250.L8
LYP000250
AU$23.78
2
AU$47.56


PYX000050.L8
PYX000050
AU$7.07
2
AU$14.14


PYX000040.L8
PYX000040
AU$7.01
2
AU$14.02


LYF000050.L8
LYF000050
AU$3.89
6
AU$23.34


LR003812.L8
LR003812
AU$72.59
1
AU$72.59


LR003813.L8
LR003813
AU$75.43
1
AU$75.43


PET000050.L8
PET000050
AU$11.69
1
AU$11.69


LVQ000040.L8
LVQ000040
AU$36.43
1
AU$36.43


LR051049.L8
LR051049
AU$43.62
1
AU$43.62


LR051048.L8
LR051048
AU$46.64
1
AU$46.64





tools:
32 mm socket for Jesus nut
27mm spanner for camshafts
water pump pulley holding tool (a must. I had to make one from steel and an angle grinder)
eBay special timing tool kit for m62 tu
long piece of steel pipe to extent your breaker bar
rave manual and Beisan systems guide

ill let you know how it all goes once done. The new chains are all on now. Just have to put it all back together...

ps FisherX: my engine was also doing the half second rattle at startup - and then sounding like a diesel if you opened the hood. I would recommend doing it asap. All of the plastic guide parts were so brittle.

[gussy]

Update.

It runs!!

Massive job. I went for a low speed drive up my road and back (<20km/h) and it definitely sounds healthier than before. Two issues to sort out tomorrow after work:

The PAS pump seems to be making some noises when I turn - belt too tight? Or loose? Rave didn’t say what deflection to put in so I just did it by feel.

There’s a flashing yellow engine occasionally. Could have been in groups of three - but I think I’ll just check everything is plugged in correctly - tomorrow.... fingers crossed [emoji1694]

[RSW Vogue 2004]

How much were the timing chains?

[gussy]

How much were the timing chains?

The Febi 47500 was $282 off eBay.
the upper set and tensioners were $75 off eBay (got a bargain though)

does anyone have the part number for the power steering pipe that connects the steering rack to the lower connection on the oil cooler. It appears the connector on that has gone on mine - I tried reseating it but it exploded putting fluid everywhere while I was bleeding it. When will it end!?!?
the hose in question is the brown one circled in red.
155771

[Laurie]

Gussy
Try this link for a parts review [wink11]

SUPPLY & RETURN HOSES - POWER STRG (M62 B44 4.4 V8 PETROL) (TO (V)9A999999) - RANGE ROVER (D4) 2002-2009 (https://allbrit.de/epc.cfm?PAGE=2110210A&CAR=TLJ&SPRACHE=EN)

Laurie

[p38arover]

When are you doing mine? [bigwhistle]

[gussy]

When are you doing mine? [bigwhistle]

Thanks for the link Laurie!

Haha P38 rover... you have the same issue? I’m happy to help out if you need. Give me a pm if you’re keen. I’ve always wanted my own engineering consultancy, but maybe I should start a Land Rover/Range Rover timing chain clinic instead. My mrs would be stoked.

[p38arover]

I think I'm a bit far away!

I also think it would be prudent to change the guides and chains now - 227K. If I had workshop space, I'd probably do it.

[gussy]

It’s finished!
Ended cutting off the propriety connector parts and used hose clamps for the power steering. The difference in power and v8 burble post timing chains and Vanos is amazing. The engine light is gone too. Must have been a loss in PAS pressure triggering it on that first 25m drive.

Now to degrease the shed...

[gussy]

I'm back!

I just returned from a 700km round trip to Margaret River and the engine was flawless.

The air suspension though...

Half way there, the passenger side has decided to lower to access height (convenient for my pregnant partner--not for driving though!) with the air suspension inactive message too. When we got to the hotel I tried disconnecting the battery and doing the lock to lock on the steering wheel after reconnection - and clearing the fault using the in dash method...

Ignition key must be “off”.
• Press and hold the Check Control button in the instrument cluster (RIGHT button), and turn the ignition key to the first position (KLR).
* You will first see "Check Control OK", some seconds later you will see "Test Nr.01"
* Push the left button on the instrument cluster to see the car's identification number. Add the 5 digits (not 6) together and write down that number, you will need it for unlocking all the functions. Example: A123457 will lead to 2+3+4+5+7 = 21
* Push the right button until you see "Test Nr.19"
* Push left button until you see the number that is equal to the one you calculated above
* Push right button again

1. Display Car's identification number, HW/SW version, construction date
2. instrument cluster self test. Will light up all lights and run all guages
3. Current consumption (liters/hour)
4. Average consumption (liters/100 km)
5. Current range
6. Remaining fuel in tank. Three sets of numbers: A/B/C. C=total amount.
7. Engine RPM / Coolant Temp (C)
8. Current Speed (kph)
9. System voltage at Term. "R" (Battery Voltage)
10. Country/Language (UK, US, Spa, Ger, Jap, etc.)
11. Units am/pm
12. Average Speed
13. ETA
14. Date of Software Mask
15. Production Diagnosis
16. ""
17. Display Vehicle Specific Data
18. Alarm Changeover (cont. vs. intermittent OBC chime)
19. Lock/Unlock
20. Correction factor for fuel consumption (nicht ändern!)
21. Reset all defect codes

To cut a long story short - it didn't fix the problem and we ended up carefully driving the wonky car 300km home. My question is: is this issue something that I need to plug a scan tool in to sort out? Does anyone in the Perth region have one that I could possibly borrow?

[FisherX]

I finally pulled my finger out and changed out my timing chains, guides, tensioners, Vanos seals and fitted a new tranny cooler.

Fairly big job about 16 hours worth for a first attempt, but could cut that down by 4 hours if I did it again.

I got sick of waiting for a UK supplier to send me a shipping quote for the kit after may attempts so I ended up taking the risk and ordering a kit from Aliexpress. Man it was cheap.

Timing kit with all guides, 3 chains, 3 tensioners, vanos and timing cover gaskets for $198 plus $55 postage. I checked all the parts out and was quite impressed with the quality. They didn't look like cheap knock offs (that I expected) and looked identical to the factory stuff. Nice machining and good quality plastics and alloy parts and the gaskets looked factory. But time will tell.

The Vanos seals were cheap too. $15 delivered with the 5 seals per side and worked ok. The tranny cooler with the Orings was $33 but $54 for postage.

The inside of my engine is absolutely filthy with a thick layer of soft crud everywhere. I guess oil changes where not that important to the previous owners. That bit me in the bum on the first test drive. I sounded great on the first start up, no start up rattle and smooth as silk. That was until I got 1km down the road. Oil light came on and the shut the engine down warning. I checked for leaks but all was good. I then pulled off the lower sump plate and OMG it was disgusting in there! The oil pick up was blocked with crud and the sump was a mess. Why would BMW make the oil pick up so SMALL! It's about the size of a 10c piece! Designed to fail maybe but that is a mod I'll be doing next oil change, I'll enlarge it to a normal size. I'll be doing 3 monthly oil changes for the foreseeable future as well.

The guides were still intact but very very brittle. The large plastic guide even broke in half when I was pulling it out, so good job done, it was defiantly due at 238 000km.

So I've just come back from a good 50km test drive and all is good. No more rattles and smoother power delivery. I'm a happy man.


AP03 18pcs Set Timing Chain KIT For BMW E39 M62 540i MODELS 4.4L REF:11311741236 11311741777 11311435028| | - AliExpress (https://www.aliexpress.com/item/32989671522.html'spm=a2g0s.9042311.0.0.39504c4d9Vq LcV)

Twin Double Seal Rings Repair/Upgrade for V8 M62TU M62 Vanos Range Rover TS | eBay (https://www.ebay.com.au/itm/114168637078)

Brand New Transmission Oil Cooler For Range Rover 4.4L W/ O-Rings Pfd000020 | eBay (https://www.ebay.com.au/itm/Brand-New-Transmission-Oil-Cooler-For-Range-Rover-4-4L-W-O-Rings-Pfd000020/222137056292'ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649)

BMW 32mm Fan Clutch Wrench Water Pump Holder Removal Tool E34/E39/E36/E46/E90 AU 541909129015 | eBay (https://www.ebay.com.au/itm/BMW-32mm-Fan-Clutch-Wrench-Water-Pump-Holder-Removal-Tool-E34-E39-E36-E46-E90-AU/143331195471'ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649)

CAM Camshaft Alignment VANOS Engine Timing Tool Kit For BMW M60 M62 M62TU M60B40 6941689828513 | eBay (https://www.ebay.com.au/itm/For-BMW-M60-M62-M62TU-CAM-Camshaft-Alignment-VANOS-Engine-Timing-Tool-Kit-M60B40/283276874712'ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649)

[p38arover]

I spoke to a LR mechanic (not from KLR) about doing this job and he said he’s never seen it done successfully in the long term. I don’t know that he has done one.

The discussion came about because I’d mentioned I’d tried contacting a BMW specialist to get a quote to do the job but got no reply.

[FisherX]

Hey Ron, That sounds strange that the changing chains, guides and tensioners would cause issues down the track. BMW guys have been doing it for years. I have heard the camshaft timing plates on the end of the vanos unit come loose and sends your efi timing out but I put a dab of Loctie on them just in case.

I've seen quotes around the 4.5K mark for the job and I can see why. I got my stuff really cheap but I've seen part prices 10 times or more than what I paid.

But what happens if you don't get it done? Jumping timing chains and bent valves, and then where do you go? Scrap the car?

Range Rover 4.4 Timing Chain Rebuild Kit (https://www.roverparts.com/engine/kits/TCKL322/)

[NUTTTR]

What are the key steps to cut it down?

In future I'll need to do guides, might leave the vanos alone as it's quiet as... But who knows what it'll be like once I get around to the job!

[glenhendry]

My turn to do this job on my 2005 4.4 M62.

164333

Took sump off, found plastic from chain guide. Will need to chain guide replacement. Anyone know where I can hire cam lock tools in Brisbane?

Also can I replace the timing chain guides without disrupting the timing?

How do I measure chain to see if it's stretched and needing replacement?

[p38arover]

Ooh, not good. The last time I took my lower sump off all was good in there.

[NUTTTR]

My turn to do this job on my 2005 4.4 M62.

164333

Took sump off, found plastic from chain guide. Will need to chain guide replacement. Anyone know where I can hire cam lock tools in Brisbane?

Also can I replace the timing chain guides without disrupting the timing?

How do I measure chain to see if it's stretched and needing replacement?

Any noises that made you look for it? Seems like a lot of guide in there!

[glenhendry]

Any noises that made you look for it? Seems like a lot of guide in there!

Yes, loud clattering one morning. Not gradual, sudden. Did not go away after a few seconds. L322 engine noise 2005 4.4 Vogue - 30 August 2020 - YouTube (https://youtu.be/3-APW2-KRyw)

[FisherX]

My turn to do this job on my 2005 4.4 M62.

164333

Took sump off, found plastic from chain guide. Will need to chain guide replacement. Anyone know where I can hire cam lock tools in Brisbane?

Also can I replace the timing chain guides without disrupting the timing?

How do I measure chain to see if it's stretched and needing replacement?



Oh that looks nasty. Definitely time to change your guides and I don't think I'd be driving the car anywhere until you do. How many KMs has your engine got on it? The job is not that technically difficult just time consuming. If you are going to take on the task I/we will be able to help you through it.


Anyone know where I can hire cam lock tools in Brisbane? You can borrow my timing kit if you would like for a case of beers and postage. I don't think I'll need them anytime soon.

Also can I replace the timing chain guides without disrupting the timing? Short answer no. The timing kit locks the cams and the crank but you have to remove the cam angle sensor plates so you need the kit to re-time them.

How do I measure chain to see if it's stretched and needing replacement? I'd say if your guides have gone the chains may have a bit of damage rubbing on the bare alloy so I'd just change them as you get them as part of the kit. Also no real way for the DIY'er to check for chain stretch to any real accuracy.

[FisherX]

What are the key steps to cut it down?

In future I'll need to do guides, might leave the vanos alone as it's quiet as... But who knows what it'll be like once I get around to the job!


The key step to cutting down on the time it takes to do the job is having done it before. Once you work out which way to hold your tongue as you squeeze the rocker covers out and back in without bumping off the gasket between the pipes and wires and the like.[thumbsupbig]

You don't need to do the Vanos seals, but you have to remove them off end of the cams if you are going to replace the small cam chains.

[NUTTTR]

Yes, loud clattering one morning. Not gradual, sudden. Did not go away after a few seconds. L322 engine noise 2005 4.4 Vogue - 30 August 2020 - YouTube (https://youtu.be/3-APW2-KRyw)

Wow, lucky catch! I'm amazed it just disintegrated suddenly!

How many KM?

[glenhendry]

Wow, lucky catch! I'm amazed it just disintegrated suddenly!

How many KM?

235kkms

[NUTTTR]

Lucky catch then! I've got 210k and considering doing it as preventative maintenance at some point... Engine is currently silent...

[glenhendry]

I have completed the tear-down, everything looks quite good except lower guide and passenger side guide are both missing plastic. Ordering parts now. Am a little nervous about all the cam timing but an awesome fellow Aulro-er has agreed to loan me cam lock tool. Very happy. Will share photos later.

[NUTTTR]

Nice. You work fast!

I assume you look on the engine bay and, basically, remove everything you can see? Most of the guides cover BMW sedans that have a lot less space in the engine bay! How many hours so far?

[glenhendry]

Well, I pulled some big hours this week because this weekend was elsewise busy, and I wanted to see the guts before I ordered parts. ~26hrs on spanners & ~15hrs of research (forum reading & youtube [I think it's sad that the Facebook 'pages' have stolen a lot of focus from the big forums like Aurlo, FFRR, LandyZone & RR.net]). I really think I could get away with just replacing the 3 guides, but given the effort to tear down, I will def do coolant pump, gaskets, chain, tensioner, etc.

I got stuck on several points:
- trying to get the RH cam cover off past the dipstick tube - it is hard to get to the bottom to unbolt it and I was scared to bend it
- trying to get the viscous fan nut off (need 32mm tool which were out of stock locally (I used a normal 32mm spanner and a big screwdriver to hold the hub))
- trying to get the lower timing cover off (there is TWENTY-ONE bolts on that thing (5 top, 5 left, 5 right hand side), and I could NOT find the last one)

164424
164425

[NUTTTR]

Ouch... Painful!

[glenhendry]

I have ordered the chain guide kit and also Vanos rebuild kit from Basien. I also ordered a new crank pulley bolt, because they say its a stretch bolt and should not be reused (at $24 from LR its not too bad anyway). What about the front cover main seal? Do L322 ones have issues? I see no stories about them online, even tho P38 suffered from them - they are $59 from LR, so if it's not leaking I may leave it be?
Thanks!

[Laurie]

Glen
For peace of mind and the small outlay I would replace the seal ! [thumbsupbig] You will kick yourself if in the future it leaks[bigwhistle]

Laurie

[glenhendry]

Glen
For peace of mind and the small outlay I would replace the seal ! [thumbsupbig] You will kick yourself if in the future it leaks[bigwhistle]

Laurie
Sorry Laurie, I should have specified that RAVE shows special tools to remove and replace that front crank seal that I do not have. I was thinking that I don't want to disrupt a working seal without assurance that I would be able to put on the new seal and have it -seal- :) I couldn't find general seal tools for a reasonable price.

[Laurie]

Glen
Is this any help ?

BMW Engine – Mechanics Tool Hire (https://mthire.com.au/collections/bmw-engine)

Laurie

[glenhendry]

This forum has an amazing amount of information on the Vanos rebuild and the timing of the M62TU.
The Vanos Forum (http://www.bimmerboard.com/forums/vanos/page/0)

My parts havent arrived yet, but I suspect I will be doing the VANOS rebuild, the reinstall, the retiming, and the startup next week. Interference engines are scary :)

[NUTTTR]

I found one post on a BMW forum (link to follow if I can find it again...) where someone did the lower timing guides without touching the vanos or cams... He tied the chain tight around the cam so it couldn't slip and same for crank end.

This appeals to me as I don't want to touch the vanos until it's really really required (timing, etc).

Is this possible? Won't be changing the chain either...

[Laurie]

I have seen a set of photos where this was done. Basically he used x/heavy duty cable ties, pining the chain to the sprockets [thumbsupbig] if I can find them I post them up later.

Laurie

[NUTTTR]

I have seen a set of photos where this was done. Basically he used x/heavy duty cable ties, pining the chain to the sprockets [thumbsupbig] if I can find them I post them up later.

Laurie

I think I found it!!!

Timing chain guides - no need for timing!!!! Not a bmw approved method !!! | Bimmerfest BMW (https://www.bimmerfest.com/threads/timing-chain-guides-no-need-for-timing-not-a-bmw-approved-method.984785/)

No pictures for me though in the thread... But that was kind of what I envisaged. I swear there were pictures last time I saw it... Unless it was a different thread

[FisherX]

I guess you could try it that way but having done the job myself I wouldn't try doing it without at least the crank and cam locking tools. The cams have a bit of tension on them and want to move a bit when the tension comes off the main chain and you have to use a 27mm spanner (or big shifter) to move the cams to fit into the cam blocks.

Doing the job with the correct timing tool kit was pretty straight forward except for one thing! The cam locking blocks are marked in German so "E" is the inlet cam and "A" is exhaust.

I'm happy to lend out my timing kit to anyone on the forum that wants to do the job themselves. Although, I paid $177 for my kit delivered from ebay so not that expensive to have in the tool box.

Also that method won't work it you are going to change the chains or the upper tensioners.

[NUTTTR]

Nice offer!

In reality, the plan would be "don't touch timing". The locking tools will help keep the tension off at least, making it less likely to slip or come off, but in the event it does come off, you need to be prepared.

I'm surprised he didn't take rockers off... The rocker cover gaskets on mine have been done twice in the last 3 years so I'm sure they'll be good for a while longer, but in reality, best just doing it properly once rather than having to repeat it.

There appeal of not touching the timing or chain is very high.

[glenhendry]

I have completed the job. It was huge wrt the number of hours, and there were some tricky bits, but nothing impossible. I ended up with some new tools in the garage. :) A big thanks to FisherX for the loaner of timing tools. They will get back to you soon.

I decided to buy the Vanos rebuild orings kit and I had to wait FIFTY-SEVEN days for them to arrive, hence the huge delay in the job finalising. Rebuilding the Vanos' was not difficult. Made me feel fuzzy too, but compressing the press was hard work, and the vice and work bench were tested. I did replace the jesus bolt, and the front main seal, it was simple to remove the old one and drift the new one in carefully without the fancy seal removal tool.

All the old gaskets were solid and brittle. No wonder there were leaks. All the connectors and tubes and hoses survived the ordeal. The oil dipstick tube in a total PITA. I could NOT get to the bottom of it to check the oil seal and clamp, and I am worried about that bit. A very very neat trick to hold the new gaskets onto the cam covers while you lower them on at the end of the whole job is to zip tie them to the cam cover (about 25 of them) - then snip them off once they are in place - thanks for that tip.

I turned over the engine 50 times via starter with fuel relay removed and the battery fully charged on the previous day. Then it started up pretty much straight away when fuel relay reinstallled. It sounded tight and amazingly quiet. I took out 8 lifters and 0 of them squeezed like I had seen in some youtube videos. I couldnt afford to replace them all, and since I had had no lifter noise previously, I left them in.

Timing the engine is not that difficult, and there is plenty of DIY videos. Neither of my Vanos's would beep the closed circuit at full retard with the DMM like the video suggest, but the Besian Systems instructions said that wouldn't always occur. I was confident that I had full CCW retard on the cam so I went ahead anyway. GAS webpage instructions were great: Instructions for the G.A.S. Master Cam Timing Tools for the BMW M62-M62tu Engine | German Auto SolutionsGerman Auto Solutions (https://germanautosolutions.com/support/bmw-tool-instructions/instructions-for-m62tu-master-cam-timing-tools/). All the coolant hoses are easy to relocate, as are timing belts.

I have smooth running, no coolant or oil leaks, with no fault codes initially, but after 10 hours I got "Lambda control adaption faults" on both banks which have not returned since cleared. I suspect fuel map is changing and I should probably clear all the adaptations with new timing belts and new vanos's.

Overall I am very happy. There was very considerable relief when she fired up and ran smooth. I spent $1420 on parts (timing chain guide kit, and vanos rebuild kit), which included ~$200 in tools. Total hours on spanners 70. Research ~22hrs. Someone with more skills or more tools could probably half that. Will be testing it by towing the camper this weekend.




Well, I pulled some big hours this week because this weekend was elsewise busy, and I wanted to see the guts before I ordered parts. ~26hrs on spanners & ~15hrs of research (forum reading & youtube [I think it's sad that the Facebook 'pages' have stolen a lot of focus from the big forums like Aurlo, FFRR, LandyZone & RR.net]). I really think I could get away with just replacing the 3 guides, but given the effort to tear down, I will def do coolant pump, gaskets, chain, tensioner, etc.

I got stuck on several points:
- trying to get the RH cam cover off past the dipstick tube - it is hard to get to the bottom to unbolt it and I was scared to bend it
- trying to get the viscous fan nut off (need 32mm tool which were out of stock locally (I used a normal 32mm spanner and a big screwdriver to hold the hub))
- trying to get the lower timing cover off (there is TWENTY-ONE bolts on that thing (5 top, 5 left, 5 right hand side), and I could NOT find the last one)

164424
164425

[NUTTTR]

Congratulations... what a massive effort! Having to wait that long for the seals is crazy!! I bet it's quiet now!

[Laurie]

Great effort Glen [thumbsupbig]

Laurie

[p38arover]

I wonder if I should do this. It seems a relatively easy job.

EDIT: I just had a look at my L322. It looks a mongrel of a job. Even with a mirror, I'm not sure I found the tensioner! [bigsad]


https://www.youtube.com/watch?v=ktEctXhtufs

[p38arover]

At 20:00 in this video one can see the timing chain tensioner being removed.


https://www.youtube.com/watch?v=bGmni3iTkhk