318IS timing chain: mission accomplished but some questions.

[tomstickland]

I finally got round to fitting a new timing chain and sprockets to my 318IS today.
I started at 12.30pm and finished at 9pm.

The crank pulley bolt was a major hassle to remove. My first attempt at a locking tool was two pieces of 3 x 20mm bar with holes drilled in them to make a triangle arrangement. This buckled once some strenuous attempts were made with the breaker bar. So I decided to make a beefier version.

First of all I had to remove the water pump to make enough clearnace. The pump did not want to come out. I used the jacking bolts and started to gently tighten them, tapping the pump with a soft mallet. I did up the lower bolt a bit more and it just snapped a load of the pump housing off. In the end I just spent ten minutes hitting the pump with a large lump hammer until it started to come out. A load of the casting had cracked off in the process, but no damage was done to the engine.

The MK2 removal tool used two pieces of 2" angle iron. A really long breaker bar was used along with about 5 minutes of heaving before there was a large creak and the bolt moved a bit.

I had a cam locking tool and crank locking tool made and they did the job really well. Swapping the chain and sprockets over was pretty simple after the difficult jobs that had already been done.

The teeth on the old sprockets were really worn - on the new pulleys there was about 3-4mm of gap bewteen each tooth cut out. On the worn pulleys the cuts out had worn so much that they touched. The guides were pretty worn too.

I messed up on one bolt and stripped the thread out. The small bolts in the alloy parts are really delicate.

Anyway a question: the Haynes manual went on and on about priming the tensioner properly. I followed the instructions and managed to seperate the plunger from the sleeve, but the instructions for pushing it back together so that the 2nd circlip locked into position just didn't seem to relate to reality. After a few attempts I gave up and just refitted the tensioner as it was.

Putting it all back together was simple enough. I found out that for some reason I had two new water pumps and two thermostats. So the spares are for sale. I had a new thermostat but no housing gasket. I made one out of some old card and smeared it in gasket sealant. Seems to work OK, but will be replaced back out sometime.

The car started straight away once it was back together, so that was good.

However, once it had quietened down after the first 30 seconds, it really didn't sound that different from how it had before I'd replaced all the parts. This concerns me slightly. I've no idea what a perfect 318IS engine sounds like, but I still think I can hear chain rattle. Do the parts take some time to bed in? Or could I have some other problem?

So, job done, but I'm not totally happy.

[M3Compact]

Great read, nice one.

The car started straight away once it was back together, so that was good.

However, once it had quietened down after the first 30 seconds, it really didn't sound that different from how it had before I'd replaced all the parts. This concerns me slightly. I've no idea what a perfect 318IS engine sounds like, but I still think I can hear chain rattle. Do the parts take some time to bed in? Or could I have some other problem?

Have you given it a rev/run?

Tensioner might not be doing its job properly yet.

[boybimmerm3]

I would replace the tensioner asap mate, if you dont set them correctly by getting it to click together properly the tension on the chain will be too much and can lead to more problems. New tensioners are not much from dealer, is not worth risking after all the work you have done.

[tomstickland]

It's a 4 month old tensioner. So it should have done the 2nd click together then? I wondered whether there was a difference between E30 and E36 tensioners and I had an E36 one or something.

OK, maybe my problems are related to the tensioner then? In which case I might as well just put another new one in and see what happens.

I might as well get a BMW part rather than motor factors this time too.

[M3Compact]

It's a 4 month old tensioner. So it should have done the 2nd click together then? I wondered whether there was a difference between E30 and E36 tensioners and I had an E36 one or something.

OK, maybe my problems are related to the tensioner then? In which case I might as well just put another new one in and see what happens.

I might as well get a BMW part rather than motor factors this time too.

The M44 chain tensioner is ok for the M42, if that's what you have?



Ԛ£50 dealer, Ԛ£14 from Euro.

Have you given it a proper chance to pump up?

[tomstickland]

Tensioner looks like the one in the photo.
I've driven it about 15 miles including motorway.
It did quieten down in the first 30 seconds. The sprockets and chain were all worn. They've all been replaced.
So maybe I'm being paranoid, or maybe there is some other problem.

[M3Compact]

15 mins on the motorway is more than enough to sort the tensioner, if it's ok.

May be worth a Ԛ£14 change imo.

[Dan318-is]

tom hjow much did it cost you in parts

an were did you buy them from??

[Demlotcrew]

There are two types of top sprockets. And they dont wear.

Did you change the guides? Did you make sure you aligned the oil holes?

A

[tomstickland]

Parts changed:
cam sprockets
crank sprocket
idler sprocket
chain
lower guide
top guide
left hand guide
tensioner guide

water pump
thermostat

That lot came to around Ԛ£400 total! I sourced many bits from GSF, but some parts were only available from BMW.

If there were two types of tooth profile, either way, the teeth were showing signs of wear, I'll get some photos later today.


Which oil holes am I supposed to have aligned? Tensioner oil feed?

[pmaddy00]

It sounds like a tensioner isnt doing its job or the guides are not properly fitted- (m44 & m42 tensioner the same part from BMW). I changed my chain two months ago (only the chain) and it sounds better than it was. I dont think u needed to change the sprockets anyway. I would take it to a proper BMW specialist to have a look at it !!

edt: There is a little round pin on the end of the tensioner (i had a bit of problem with it) ..make sure it is in ..try to use a flat screwdriver to push it (tensioner) from the guide end.. and see if the mechanism works.

[tomstickland]

I'll take some pictures of the sprockets later. They were not in a good shape - obvious signs of wear on the teeth etc. I've read up on it and the sprockets and chain should be changed together, just like on mountain bikes etc.

I've done some fiddling around with the tensioner today. If I take it out and crank the engine over then it sounds really bad. So the tensioner is obviously working. With the tensioner in the engine doesn't sound really bad, but to my mind, it doesn't sound as quiet as it shoud. If I have the bonnet open and rev the engine then I can hear what sounds like chain noise. Thing is, I have no idea as to what is normal, this being my first 18IS engine.

I also took the tensioner apart to inspect it. I found that the outer circlip was too small to engage in the groove on the inside of the sleeve. So I enlarged it slightly and was then able to replicate the method shown in the Haynes manual. Only one problem then though; because the engine is assmbled I can't release the plunger as described. Hence I think it's best to release the plunger and just refit the tensioner.

I can see what the danger is - if the plunger is fully extended then it can go past the feed hole in the sleeve and the oil can then only lock it outwards.

Anyway.... my thoughts are:
1) Tensioner has some issue. This doesn't seem very likely to me, but another one would eliminate that question.
2) I didn't fit the parts properly. I'm confident that I fitted everything as instructed. I've spent a good few years doing DIY engine work and everything was inspected closely as I did it.
3) There's some other issue with the engine. For example, could the oil pressure to the tensioner be low?

I'll call round the BMW chap on Tuesday for an opinion. If there is something else wrong with the engine then I'm probably just going to drive it until it becomes more serious anyway; I bought this is a cheap car and I've already spent a bit too much.

EDIT: little round pin? The end of the tensioner is flat with a small hole in it.

EDIT 2: I've just been reading http://www.esatclear.ie/~bpurcell/318ismaintenance.html
and he says

Install the chain tensioner. If you are reinstalling the old one, you may need to compress it in a bench vice (it should click) before reinstalling it - but you may be able to compress and turn it at the same time with a ratchet and socket (I did!).

that's what I did (compress and turn at same time)

also

Start the engine and bring it to 2500rpm for ~30 seconds to release the timing chain tensioner (if new).

That's what I can do now that I've compressed the tensioner.

[tomstickland]

I understand it all know. The Haynes description is not very good. On the end there are two grooves and the ring is supposed to sit on the larger of these two when the unit is compressed. Pushing any further causes the ring to move down on the lower groove and then it no longer touches the sleeve and so releases the plunger.


My experimentation involved enlarging that ring, so now it doesn't release at all. LOL. Call it 1 - 0 to new knowledge over actually being anything to do with the problem.

I've cranked the engine over with the tensioner removed and oil gushes out of the hole, so I'm assuming that the oil supply is good and as intended.

[boybimmerm3]

dont crank the engine over with the tensioner out or else you can cause damage. ok if you dont fit your tensioner new or old correctly you are going to damage too. if you refit your old one it has to be in the correct state to do so first, if you get a new one it will already be in the right state to fit. once you fit the new tensioner you need to release it, to do this you need to move the timing chain guide towards the tensioner and this will then release the tensioner and take up the correct slack on the chain. once you start the engine with a new tensioner you have to rev the car to 3500rpm for 20 seconds to fill and bleed oil in the tensioner. if you try and not do this part of the job you are risking your whole engine. hth.

[tomstickland]

I don't understand what's wrong with taking it in the extended position and then pushing it into the hole. It's still ending up compressed. That's what that 318IS site says he did.

Anyway, new tensioner tomorrow.

[tomstickland]

UPDATE:
new tensioner ordered for tomorrow.

I've spoken to a few people and the hydraulic lifters have been questioned.
As well as some timing chain rattle, there is also a "diesel engine" noise at about 3000rpm. It does sound very tractor like.

I priced up new tappets and they're Ԛ£9 each, so I'm looking at around Ԛ£170 for a set inc VAT.

I'm happy to swap new ones in if it fixes the problem; I bought this as a cheap car, but I'm not short of cash and I want it to work properly. I've comitted myself now anyway.

Bear in mind the history of the engine: head gasket went, a new head was fitted, this was cracked, so another head was fitted. All by previous owners/garages. So there is the possibility that the lifters/top end lubrication suffered at some point.

UPDATE 2: I called round the local BMW independant garage and the chap had a listen to the engine. "sounds fine to me" was his verdict. So maybe the timing chain etc is fine. The engine still sounds a bit rough to me mind you.