Cam tray removal question.

Specific conversations and info for the BMW E28 M5 and M535i.
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demetk
Posts: 8431
Joined: Aug 09, 2007 8:58 AM
Location: CT, USA

Cam tray removal question.

Post by demetk »

I have coolant in the oil so the head is coming off. Can somebody provide a link on a how-to on removing the cam tray?

I'm at the point where I'm ready to do that but I'm not sure if the cams need to come out first or if the tray can be removed with the cams in place.

TIA
Philo
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Joined: Feb 12, 2006 12:00 PM
Location: Long Beach, CA

Re: Cam tray removal question.

Post by Philo »

To get the cams off there's a special BMW cam removal tool that holds the cams down while the nuts are taken off. But it's really rare and very expensive. I don't even think you can rent it.

So, What I've done several times is set the crank at TDC and then loosen the cam nuts a quarter turn at a time, working front to back, until the valve spring pressure is off all the cam lobes. Putting the cams back on is the same process. Just go slow and try to keep the pressure even.

As for the cam tray, it's simple, there's just a ton of hex bolts and frankly is a pain is the ass. Prior to taking the cam tray off though remove all the lifters and keep them in order so they back in their same lifter position when you put the engine back together.

Note, there is no gasket between the head and the cam tray, just clean it up and use Hylomar to create a liquid gasket when putting it back on.
Image

I'm guessing you already know how to take the head bolts off in a pattern ?? A nd put them on the same way with final torque specs ? If not let me know and I'd be happy to do a call with you.

By far the hardest part in my opinion will be getting the header nuts off. Some of the nuts wont come off and you'll end up pulling the header studs out. Not a big deal, you'll just need to put them back prior to putting the headers back on.

Post or call me if you need anything else. I also have a bunch of pics from the last time I took an S38 head off.
310-766-1923
demetk
Posts: 8431
Joined: Aug 09, 2007 8:58 AM
Location: CT, USA

Re: Cam tray removal question.

Post by demetk »

Philo, thanks very much man. This is extremely helpful. I'll tackle this next weekend and let you know how I fair. In the mean time I'll order the Holymar.

ahab, if you're reading this you're welcome to come over and laugh at me while I do it.

So how come the cam tray can't be removed with the cams in place? Is it because there is no room to get at the allen bolts?
41magfan
Posts: 103
Joined: Nov 07, 2013 5:38 PM

Re: Cam tray removal question.

Post by 41magfan »

Philo is dead right, but to add, make sure you are using a quality allen socket to remove the cam tray bolts or you risk stripping them. I have even gone so far as to tap the allen socket with a hammer before turning them the first time

In addition, I used 3 different tools in removing those lovely little 9mm exhaust nuts
1) std 9mm 1/4" socket
2) universal flex 9mm 1/4" socket
3) 9mm wrench
Randomg
Posts: 480
Joined: Jul 12, 2007 3:12 PM
Location: Seattle

Re: Cam tray removal question.

Post by Randomg »

On reinstall, make sure you clean out all of the holes of oil. I reinstalled it with the exhaust holes full of oil and tried to torque them to spec and stripped nearly all of them and had to go back in and helicoil very carefully. There might have been some other variables leading to this happening to me since cleaning out the holes is not in the official procedure, but I say better safe than sorry.

Lastly, make sure you match the cam caps, letters and numbers. E to E, A to A. E is for intake in German...
demetk
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Joined: Aug 09, 2007 8:58 AM
Location: CT, USA

Re: Cam tray removal question.

Post by demetk »

Thanks for the comments guys. I'm going to heed your advice.

What brand of allen sockets are you guys using? I'm pretty sure the ones I'm using are from Autozone or HF.
demetk
Posts: 8431
Joined: Aug 09, 2007 8:58 AM
Location: CT, USA

Re: Cam tray removal question.

Post by demetk »

Cam tray is off! Stripped one cap screw because it was in there really tight. I managed to get it out by tapping a SAE socket into it and it came off. Noticed one cap screw is $9 at ECS. :shock: Anywhere else I can source them cheaper?
Philo
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Joined: Feb 12, 2006 12:00 PM
Location: Long Beach, CA

Re: Cam tray removal question.

Post by Philo »

Glad others joined in here... this can be really stressful the first time around. But overall it's no big deal really :)

41magfan - I can see you've been down this road before. Yes, those allen screw can be a pain in the A.

demetk - did you finally figure out why the cam tray has to come off before the head ?..... :D Regarding buying new hardware, I purchased mine from the dealer 5-6 years ago and they were pretty inexpensive at the time, so check them out before ECS. Also, you know you can use any similar allen bolt, right ? There's no magic hardware being used in these old engines. Hell, tell me how many you need and I'll mail them to you. I think I have a dozen or so.

Just be thankful you don't have Euro headers. Getting the header nuts off with the snakes is twice the pain in the butt.

Let me know if I can be of help,
Randomg
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Joined: Jul 12, 2007 3:12 PM
Location: Seattle

Re: Cam tray removal question.

Post by Randomg »

Philo wrote:Glad others joined in here... this can be really stressful the first time around. But overall it's no big deal really :)
It's not stressful, but be methodical, as mistakes are a pain. I've made them all short of snapping a cam due to my negligence of thinking "I've done this before, I can rush this and not pay attention".

Make sure you get the head clean before you put on the new hylomar, and I personally try to over apply it if anything since the alternative is a hard to diagnose and fix intake leak. I also tend to put more towards the front since there are only those 5 small bolts along the timing chain compared to the very close together m7 and m8 bolts/nuts.
demetk
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Joined: Aug 09, 2007 8:58 AM
Location: CT, USA

Re: Cam tray removal question.

Post by demetk »

Glad you guys are chiming in with your experiences. They have increased my confidence at moving ahead. ahab was also kind enough to send me this doc which I read a couple of times already.

https://www.google.com/url?sa=t&rct=j&q ... DptDKxD3Cw

I wouldn't have thought to move the crank 60 degrees before putting the head back on to provide piston clearance when installing the cams.
dsmith
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Location: Charleston, SC

Re: Cam tray removal question.

Post by dsmith »

That is exactly what I was going to link and warn about. Very important step, that little counter rotation. I sucked all of the coolant and oil out of the block and head bolt holes with a mityvac.
demetk
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Joined: Aug 09, 2007 8:58 AM
Location: CT, USA

Re: Cam tray removal question.

Post by demetk »

When I was at the final stage of releasing pressure on one of the cams it suddenly rotated a bit. At that moment my heart stopped for a nanosecond or two. I reflected on what happened and I figured this could be a problem when they were reinstalled with the engine at TDC. It was only when I reread the doc later that day that I finally understood that sentence of moving the engine off TDC.

Keep the tips and tricks coming guys. My engine's future survival may depend on them. :)
Last edited by demetk on May 31, 2017 11:01 PM, edited 1 time in total.
demetk
Posts: 8431
Joined: Aug 09, 2007 8:58 AM
Location: CT, USA

Re: Cam tray removal question.

Post by demetk »

dsmith wrote:I sucked all of the coolant and oil out of the block and head bolt holes with a mityvac.
That's a great tip. Thanks.
demetk
Posts: 8431
Joined: Aug 09, 2007 8:58 AM
Location: CT, USA

Re: Cam tray removal question.

Post by demetk »

I'm afraid using a mityvac is now going to have to wait.

Got the head off and found no issues with the head gasket so the question of the milkshake oil has not been resolved. But I found major issues with the bottom end. Looks like someone previously got in there and honed the cylinders to the point where the pistons are now nice and loose. I measured over 25 thou clearances on all pistons. I'm pretty sure this explains the low pre-purchase compression numbers. :(
Syndrome
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Location: DC

Re: Cam tray removal question.

Post by Syndrome »

Hello everyone. I was searching for the right sequence and torque specs to get my S38B35 cam tray torqued down properly and ran across this thread. Can anyone tell me how to do this, please? Thanks.
Randomg
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Joined: Jul 12, 2007 3:12 PM
Location: Seattle

Re: Cam tray removal question.

Post by Randomg »

I don't believe the sequence is that important since the service manual doesn't specify, but I guess preferred sequence would be the same as the head: start in the center and work your way out, crossing to the other side for every fastener. 13mm nuts (and the 14mm tensioner spacer and the tensioner allen head bolts) should be 22 nm. The m7 allen head bolts are 15 nm.

Mounting the cam is different. Rotate the crank about 30 degrees from TDC so that none of the pistons are at the top and then lay the cams in closest to their TDC position. Each cam has 2 marks since it can be used for intake or exhaust. For the each side, you want to use the mark that has the front cam lobe point diagonally up and towards the center of the engine, so the exhaust points up and to the right, the intake points up and to the left. You also probably want to look for a mark on each cam to see if it's marked I or E (in German E is intake and A is exhaust). I think in general if you have one cam from a B36 like I do, it goes on the intake side for best performance. The cams are probably the same though.

The cams will be difficult to keep at their TDC position while you install, but you'll move them to the correct position once they're tightened down. Make sure to match the cap labels and orientation. A1 for instance should match A1 on the cam cover, and the letters should point the same way (when you install it, you should be able to read A1 twice without one of them being upside down). The goal when tightening them should be to move across each the bearing caps and tighten each a little so that they stay at the same height. I do a half turn of each nut and move back to front until they're all tightened.

Once the cams are tightened, you can move them into their TDC positions by using two bolts on the end where the sprocket side and a screwdriver. Then you can rotate the crank to a little before TDC. Put both cam sprockets under the chain because you get one of them in place you won't have room to put the other in. The intake cam sprocket has a raised center to match the height of the exhaust cam sprocket when the distributor adapter is installed. They should also have E (for intake) and A (for exhaust) if they haven't been worn off.

Pull the chain tight and make sure both links fit on to the idler sprocket (it's possible the idler sprocket can be slid far enough in one direction that only one row of teeth is on the sprocket) and get the intake sprocket on the right links so that it's a little counterclockwise from linking up with the holes and guide pin (since the crank isn't TDC yet). Then do the same for the exhaust cam. Then as you rotate the crank clockwise to TDC, it should tighten the chain and pull the intake sprocket into a position that can be pressed onto the front of the cam. The exhaust cam sprocket should also be in a position to be pressed on.

If you can't get the exhaust sprocket on, you can turn the crank a little counter clockwise and then turn the intake cam a little counter clockwise so you have more slack in the chain. What's important here is that the number of links between the two sprockets stays the same. If you have some m6 studs, you two to put through the front of the intake cam and can then use a screw driver to move it a little counter clockwise. Once both are installed, torque down 2 bolts on each sprocket to hold it in place and turn the engine over slowly by hand. after a full turn you should see the TDC mark on the crank matching the TDC marks on the cams. I think it's possible the cam marks can be a little to the left when crank is at TDC because the chain can stretch over time. I also think the cam marks can be a little to the right because installing the chain tensioner does some extra stretching of the chain. The goal ultimate goal here is to make sure you're not off a tooth on the chain. Both cams should be off by the same amount and the cam TDC lines shouldn't be way off. Finally tighten the sprockets to spec, don't forget the exhaust distributor adapter.
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