1986 190E 2.3-16 Chain Guide Rail Replacement - PeachParts Mercedes-Benz Forum

JimSmith · #1 05-08-2007, 04:38 PM

A question concerning the replacement of the chain guide rails - can this job be done with the head on the car, or is it required to remove the head to get the main rail and the lower guide out? What about the intermediate rail below in the intake camshaft sprocket?

We have a unit that is eating these items. It ate the guide below the intake camshaft sprocket about two years ago and that caused all kinds of problems with oil pressure. We removed the remnants from the oil pan and the oil pump suction strainer and things returned pretty close to normal. It seems at about the same time we have developed a means for gasoline to mix with the engine oil which also adversely affects the idle oil pressure and the characteristics of the oil, so this car gets lots of oil changes while we try to figure that item out.

Today we noticed some rattling noises from the front of the engine and took the valve cover off, only to notice the main tensioning rail (on the exhaust camshaft side of the engine and it is the rail in contact with the chain tensioner) was worn away to the point where the sides of the rail protrude past the chain at the top of the rail. The chain is still reasonably tight but it would seem this item is due for replacement.

So, can this job be done without removing the head? While we are in there we would also like to replace the oil pump.

Any input would be welcome. Jim

Racing · #2 05-08-2007, 06:51 PM

No.
At first glance,one might think it could be pulled off...but nope..
Prob is that the tensioner guides on a lower sort of fulcrum pin,and this will in effect together with the lenght of the tensioner make a swap a no can do as you won´t be able to get the tensioner either in or out really.

A word of advice.
The OEM headbolts in plain english sux.
Have them swapped for a set of M12*110 allen of 12.9 quality.
Torq head to 10kgm...have the engine heat cycled a couple of times and retorq the head again.
You will NEVER have a blown headgasket EVER again.

Pumps seldom go awol on the 102 engine.
What does is the pressure relief valve.
Reason being that someone didn´t do their homework as merc as the plunger(piston) is out of stainless and it registers and runs in a cast aluminium housing-which over time will make the pressure relief valve gall-which will make it stick-and always half way of course.
Easy to remedy though.
Just ram a piece of wood up the fabled behind of the relief valve and smear it with some fine valve cutting compound and go at it.
Couple of time up and down does it,and be sure to clean the bore out with the degreaser as you´re done.

As for the fuelwash...
Depending of the amount of money you´re willing to part with...toss the POS KE out of there and go stand alone.
You´ll never look back.
Trust me on that.

JimSmith · #3 05-10-2007, 06:39 PM

Thanks. So today the we mined our way to the head, and should have the head off before the weekend. My next quandry is, I really don't want to drop the transmission, but I need to lock the crank to get the crank pully and dynamic balancer bolt out to remove them. I figure this is going to be a pain the hiney as that bolt gets a serious torque value (220 or so ft.-lbs) and is likely in there pretty good by now. Putting that kind of load on the transmission and clutch is a bit of a concern. Seems the whole system is intended to take about that number, but if breaking it loose take twice as much, are we likely to damage something?

Thanks, Jim

JimSmith · #4 05-10-2007, 06:55 PM

Racing,

Is 10kgm equal to about 72 ft-lbs? Seems to be by just converting kg to pounds and meters to feet and multiplying it out. 72 ft.-lbs seems a little light for a head bolt.

Also, I have been checking sources for these bolts, which I take are 12mm diameter and 110mm long with a grade 12.9 steel alloy. Did I get that right? Thanks, Jim

Racing · #5 05-11-2007, 03:27 AM

Jim.
http://www.102983.org/gallery/thumbnails.php?album=lastupby&uid=3

On there you´ll find numerous pics of various stuff off the 102.983 engine.
Check it out as some at least might be of help and service.

As for the crank bolt.
Unbolt the crank pulley.
Install a pair of M8 bolts as deep as they go that are to long.
Put a breaker bar between these two throw away bolts(they´ll be as you´re done)
Now let the breaker bar rest against the frame member and go at it with a 27mm socket at the crank bolt.
Be sure you have the breaker as close to the dampner as you can for less leverage on the two M8s.

Install is the reverse of removal,and make DAMN sure you tighten the center bolts per spec.

If need be pick up a dampner puller for one of the domestic engines(V8) as these will fit the 102 motor as well-and what´s more is that i bet they can be had dirt cheap at your local NAPA or similar.

12.9 bolts are a euro nomer.There´s really no equivalent in "grade" form,and the closest you´ll get is the lower settings of NAS/AN.
IOW,the 12.9s are some serious fasteners,and their torq yield depends on lenght of course.If memory serves me they indeed are 10kgm.
Yes,the 12mm of 110 lenght is correct.Don´t forget to put the OEM headbolt washers on them though.

When it comes to getting the head off.
Only thing that might get you into trouble is the water pipe that has to come out that is bolted to the head inside of the thermostat housing.
Thermostat housing...
Be careful.
Unbolt the 4 M8s for it and losen the worm clamps for the transfer hose to the pump.
Then pry/rotate the thermo housing gently...persuade it...and it´ll come off.
Thing is that it´s sealed with an o-ring that might have corrosion on it..and if you go overboard with force the transfer tube taht goes in the head might break off.

When getting the transfer tube out.
DO NOT PULL ON IT.
Get a pair of vise grips and gently rotate it back and forth while excerting a SMALL amount of pulling for every time going back and forth..and it´ll come out.
Again...amount of pulling force on both these cast aluminium pieces to be held to a minimum.

Man vill HAVE to come down.
At least a little bit,point being that the oil pump strainer is bolted to a bracket that sits on one of the main bearing saddles.
An M8 nut that needs to be unbolted-IOW you at least need to get you hand into the oilsump with a 13mm wrench to reach it.

JimSmith · #6 05-11-2007, 09:45 AM

Racing,

Thanks for the advice. That is some 16-valve you have. I can't read the language, but it looks like it is turbocharged and intercooled and that you did everything, from turning the pistons down to installing a different oil pump and drive.

Are you saying I will have to remove the transmission to enable me to drop the oil pan and remove and clean the oil strainer?

We got the thermostat housing off, along with the coolant pipe that goes through the chain box without damaging either. This is the third 190e 2.3-16 we have taken the head off of, and the first to get that pipe out cleanly. The other two it just broke off and we had to knock it out of the head once the head was off.

Is there a site or reference material for taking the front cover off? I am imagining a bunch of the rotating items inside the chainbox area are supported at the block and the front cover. I would hate to find out I broke a bunch of items by pulling the cover off out of sequence. The manuals I have are not very specific - the MB manual is only for the items that are different from the regular 190E 2.3. Apparently this cover is not.

When we got the pipe out of the chainbox I got a glimpse of the rail. It is eaten away down to the point where the tensioner contacts it. The chain itself looks fine, but the tensioner rail now has two "ears" that the chain passes between. I am wondering just what might have caused this. Any ideas? I want to make sure I fix it when I put the engine back together.

Well, thanks for the link to the site, I enjoyed the photos. How fast is that turbocharged and intercooled machine?

Jim

Racing · #7 05-12-2007, 03:32 AM

Jim.
I build them.
It´s what i do.
So..there´s been several over the last couple of yrs.
Mine has run the quarter in low 11s approx,but new motor is coming up shortly that puts out more power.
Hope for new engine to pass 650hp on the boost.

Timing chain cover.
Only thing that registers on the front cover is the axle/gear for the distributor really.
This isn´t something to be conserned of as long as you´ve released the tenstion of the chain.

Reasons for the chain eating the guide alive are either that the chain guide plastic material has gotten old and deteriorated over time or that the tensioner has go ape rendering a WAY to high pressure on the chain.
This is turn CAN be a function of a stuck pressure relief valve,and if so this will mainly be a prob with cold engine-as oilpressure can go through the roof in such scenarios.

http://www.youtube.com/watch?v=wnm5Pg6ceaw

JimSmith · #8 05-12-2007, 07:46 AM

Racing,

Thanks for the information once again. I will take some photos of the tensioner/guide rail this afternoon and post them.

I gather the revised inlet ducting in some of the photos is for the new engine? 650 hp from that basic engine volume and mass sounds like it is pushing the envelop of the materials. Do you make significant modifications to the cooling system as well?

We don't have a garage and it rained a bit yesterday so we are behind schedule by half a day or so. Today is looking a bit nicer, but we have rain forcast again for tomorrow. Wil try to have the head off today.

Great shots of the car performing in the video. I think I saw your machine with the red valve cover in the one showing a 2.5-16 Evolution II event at Hockenheim that came up after your video. I thought I recognized not just the red valve cover but the exhaust header/turbo installation.

Thanks again, Jim

JimSmith · #9 05-12-2007, 03:36 PM

Racing,

We tried the method you described for the crank pulley removal and I will post some photos tonight. The bolts are M6, not M8 on this unit (it is a 1985 Euro model) and so we fashioned a strongback that we bolted to the face of the balancer and reacted the torque on the frame rail just below the self leveling system hydraulic flud reservoir (took it out of the way). That worked, but that was no 200 ft.-lbs. What is the procedure for putting that thing back in there?

The next problem is the balancer is not one piece. The outer half came out, loose, not even attached to the inner part. No signs of any metal distress at the metal bore in the center, it just looks like it was always two pieces. Is this normal? I think we will have to buy a new one by the looks of things. But, now how does the inner half come out? Looks like a very tight fit. I will post a photo of the part that came out later too.

I can see the sleeve with the woodruff key in it inside the bore through the chainbox housing cover. Looks like a very tight fit. I tried tapping lightly on the half of the balancer that is still there and it doesn't seem to be interested in suggesting it might be loose.

Well, got to go back and try some more stuff. Jim

Racing · #10 05-13-2007, 04:15 AM

Jim.
There´s supposed to be a black coloured "sleeve" behind the balancer on the crank snout.Has a recess for the woodruff as well.This sleeve is imperative as it goes between the dampner and the chain gear and it is the drive for the oilpump.(Hence why the torq of the center bolt is so important)

However,i´ve personaly never seen a balancer like yours.
All the ones i´ve ever seen has sort of a protruding center where the pulley bolts up,and they have all sported 8mm allen bolts to keep the pulley in place.
So..in essence,that pulley of yours beats me at least.

PS/AC bracket.
This can be a real creeper...
Thing is,at the bottom of it(longside) there´s a recess that hides a long ass M8 bolt away.Sort of towards the front of the engine,fairly low.
What ads insult to injury is that this recess often gets filled with crud over time making the bolt head more or less invisible,but rest assured...it´s there for you to find.Easiest way to clean it out is by compressed air really.
Bracket can be either cast aluminium or detroit wonder metal.
On an 85 though it´s most likely aluminium.
Oil cooler hardlines need to be shifted a little to get the bracket out of harms way.Just use your pry bar for this as the hardlines are out of common black steel(altho anodized) and will take the minute leverage needed with a breeze.

Bigger issue though is all of the aluminium residue and shrapnel within the oiling sys of the engine.
Get the oilfilter out.
Use a plastic bag of some sorts,wrap it over your one hand and take it out.
Go aside,so not to mess up everything in sight.
Let it drip off a little.
Now pry the element apart.Crevis by crevis.
Check the amount of residue and left over in total.Anything more than a tea spoon full= deep up **** creek.
Oil filters are cheap,but the main problem here isn´t the filter....but the cooler.
Openings of the cooler element are VERY small,and it won´t take much for small amounts of parts/crud to slam the openings shut.Which upon reassy can decide to come lose at any time down the line.
What makes the issue worse is that the cooler is there right by the filter housing and ports for it,leaving you with a situation where the cooler WILL take the first hit with engine warmed up.
Long story short,you´re out an oilcooler.No two ways about it.
If you wanna save a buck or two try looking a "Setrab" up instead as the OEM Behr are an arm and a leg.Wild guess is that a Setrab one is approx 1/3 the cost of the OEM one-and frankly just as good.(Setrab is OEM for ferrari for instance).In such a scenario,count on looking a hydraulic vendor up to get new hoses and fittings.

Now for the culprit.
Obviously something´s had the tension of the chain go ape,because no matter the plunger in itself isn´t supposed to go far enough for the damage seen to happen.By half way approx it´s supposed to be far "over edge" as far as any control of it at least.
This also points to that you must have heard large amounts of racket on startup especially-before the pressure hit the tensioner.(Cold engine)

Further,seing the amount of residue....
Jim.
This is going to take some brass balls,but there really only one option here.
Clean what´s been mentioned out to the best of your capacity.Especially so the bore of the oilpressure relief valve.
Pick a number of oilfilters up.
Pan HAS to come completely off for you to;
a/clean it out completely.
b/clean any residue off the crank case walls with common engine degreaser
c/Clean the rest of the engine out to the best of your capacity.

DO NOT AFTER RINSE WITH ANYTHING THOUGH.
Just liberal amounts of petroleum based engine degreaser.A brush certainly helps.

As you have the front timing cover off,just bolt the oilpump apart and be done with it.Check for wear and end play of pump.If "lid" of pump is full of marks,this can be handled easily by simply trueing it against a known flat surface-like a piece of glass.
If you use emery cloth,spray alcohol of some sort at it to keep it moist and to prevent the aluminium from sludging the paper up.

Pickup tube...again...engine degreaser to the point of diminishing returns.

My bet is that a stuck oilpressure relief valve caused this.

..and in all honesty...
One thing that is DIRT cheap for these engines is the late style con rod bolts.
As you have the pan off anyways it would be pure folly not to take the caps off the conrods to have a look at the condition of the conrod bearings at least.
If the conrods are the early style you won´t need new nuts n bolts,just reuse what´s there and torq to 60Nm.
Early style have nuts pointing towards you(14mm socket if memory serves me) and the later ones 12 pointed 10mm bolts.
If the conrods of your motor are the early variety....smile...cause those rods will take more or less anything you throw at ém..(They´re about twice as beefy as the later ones)

If the later variety bolts you absolutely NEED to replace them,but as noted they´re dirt cheap-and you order them by the piece.
Likewise,conrod bearings ain´t an arm and a leg either.

Reasons for doing this is plentyfold.
Major one being that you´ve had crud running through the engine and the conrod bearings are the ones that always takes the hardest hit from any perspective really.

All 8 conrod bolts/nuts can be accessed with the motor in place.There´s even sort of two small reccesses in the front crossmember for the extension shafts needed for your torq wrench.(No 2 and 3 cyl)

JimSmith · #11 05-13-2007, 09:02 AM

Racing,

Thanks for the time to post such a detailed response. I am struggling with how to get the oil pan off without taking the transmission down. The car is "on the ground" so to speak, meaning it is sitting on the tires and we use a floor jack to lift it now and then to get under it. Dropping the transmission is almost out of the question now.

We can probably get the oil pan down a few inches by disconnecting the engine mounts and trying to block the engine up, I suppose.

As for the oil system, this car has been on Mobil 1, 5W-40 (sold here as Delvac 1, a Diesel engine oil with additives for keeping the soot in suspension) for quite some time, like the last 20,000 or so miles, changed every 5,000 miles or less. We have had a problem with gasoline getting into the oil, and as of late the car has had oil changes every 2,500 miles. That turns out to be leaking injectors. My son has the car at school in Indiana and we live in Connecticut. We have been looking at the oil filters and have not noticed a lot of serious crud in the past, but will take this one out and check it carefully. We usually change the oil hot, and I have the last discarded oil change (about 1,100 miles ago).

I will go outside and try to take a photo of the woodruff key, as well as try to find the part numbers for the dampner(s) and the pulley. Maybe I can track them down that way. The first owner of this car was from California and drove it in local road races and the like at one of the tracks near Los Angeles. It is possible he put something peculiar on it.

If I take the oil cooler out and send it to a local repair shop and ask them to flow solvent through it, would that be of any use?

So, my next big challenge before I can respond to the lower end work you recommended is getting the oil pan off. I will have to study that for a while.

Thanks again for the help, Jim

JimSmith · #12 05-13-2007, 09:40 AM

Racing,

Very difficult to get a photo, but there is a sleeve like thing on the shaft snout behind the Woodruff key. It isn't black, though. I also wanted to point out the two piece thing seems to be intentionally a two piece thing. The inner part has a slot for the Woodruff key and the outer half doesn't.

I will get some part numbers and start searching, but if you have never seen them I am really wondering what they are. I hope I can find a brand if it isn't an MB part.

The tensioner plunger has a snap ring that is supposed to engage a groove in the cylinder to prevent it from coming out all the way. When we got it out, the snap ring was all that was holding the plunger inside the cylinder. I think the new style ratcheting chain tensioner is needed. They are wildly expensive here though.

I think most of this damage had been a result of the last maybe 3,000 miles as we adjusted the valves in March and only the exhaust valves needed to be adjusted. So, we spent a lot of time peering in and around the chain tensioning rail at that time and while I cannot say I recall examining the chain and the tensioning rail then, I am also fairly certain that the visible damage we saw this time when we took the valve cover off would not have been overlooked. The oil was changed at that time, before the trip back to West Lafayette, Indiana (about 900 miles) and then again before returning due to the gas contamination.

Well, off to set up for the cover removal. Thanks for the hints on the bolt hiding in the gunk. Some parts of this engine are sparkling clean, while others are filthy. The area around the bracket is filthy. Wonderful.

Jim

Racing · #13 05-13-2007, 05:12 PM

Quote:

If I take the oil cooler out and send it to a local repair shop and ask them to flow solvent through it, would that be of any use?

Answer is simple.No.

Gettin the pan off with motor in the car is doable though.
Drop the front sway bar-as in get it out of there.
Rise the motor as high as it will go with the mounts unbolted and block as u suggest.

Now unbolt the pan.
A large number of M6 bolts(metric 10 wrench),3 or 4 M8s(metric 13 wrench) and the 2 M10s from the trans side(metric 17)
Drop the pan as far as it will go and slide it forward until is starts to droop.
Then slide the pan sideways...and out she comes.I guarantee.

Now you can get a clean view of the bottom end as well as unbolt the pickup tube et al.

Racing · #14 05-13-2007, 05:12 PM

Btw.
My money is still on a stuck pressure relief valve.
Farily common issue with these engines,and something that should ALWAYS be serviced as you have it apart.

JimSmith · #15 05-13-2007, 05:39 PM

Racing,

Thanks for the encouragement. We spent a bit of time honoring the mother of my kids today, but my son was under the car for more than 4 hours anyway. He invested a bit of time cleaning up and getting ready to try to drop the pan. Thanks for the encouraging words and suggestion to turn the pan sideways to get it out. So, out it comes, next.

Tomorrow will be a slow day as for most of us, it is a work day...even the son will be goiing to work at the local golf course, tending to the greens and fairways. So, daily progress is going to slow down.

Once we get this done we will consider taking the head and front cover off the 1988 300E. It has an oil leak at the right front corner of the head and front cover that just pees that Mobil Delvac 1. About a liter every 1500 km.

Will continue to keep you posted and once again, thanks very much for the help. Jim