Mi Tappet Noise

[jerseypug 1]

i have done a search for noisey mi tappets and loads came up with the same problems i have. it seems to be after the head has been removed then replaced there is a loud tapping from one or more of the tappets. in all the topics no one has mentioned if they have cured the problem. i am hopeing that the problem is that the tappets are dry and takeing a long time to re fill with oil. it would be nice to know if any of the people who had the same problem had to replace the buckets or if the noise eventually went away.

[C_W 3 1 Cars]

The engines sound a bit tappety any for hyrdraulic followers buthey should make pronounced tapping noises.

 

You can tell which is dodgy as it will push down easily if you take the rocker cover off and press on it with a screwdriver.

 

If the head's been off or the engine hasn't run for a while then idle it at 2000rpm for about 20 or 30mins.

[jerseypug 1]

i have done about 40 miles takeing it easy with a short burst now and then. i dont know if i should keep driving it as it might sort itself out or it might do some damage. i might take the rocker cover off again and see if i can push any tappets down. What is the best way to do this, push them with a thin piece of wood?

[jerseypug 1]

Seems to be quieter especially at tick over but still does not sound healthy when driving it. I removed the rocker cover and tried to push the buckets but none seemed squidgey. There were 2 that were moving but I think I was pushing the valve down. I will persevere. Apparently the bucket only primes with oil when the valve is shut. I could have crap in the bucket stopping the one-way valve from shutting. Any ones opinions would be gratefully received.

[boombang 2]

Sure this noise is coming from the head?

 

If there is no clearance cam to lifter then it shouldn't make a rattle.

EDIT:

 

did you not put the head gasket the wrong way round? wondering if somehow that's done the bottom end? check the lifter to cam clearance and if there is clearance take that lifter apart, clean out with brake cleaner, leave to dry, fill with oil and refit. Maybe get a screwdriver and listen to the head to try to work out precisely where the noise is coming from?

Edited November 10, 2006 by boombang

[jerseypug 1]

After putting the head gasket on the wrong way, it was pulled apart as the seals between the liners had gone so while it was apart the big ends were changed and everything was checked.

I have a stethoscope that I use for these types of rattles and the noise is loudest at the rocker cover.

Didnt really want to do the cam belt again but looks like I am going to have to.

How do you fill up the lifter with oil after it has been cleaned?

[dommorton 0]

Any chance you could have slightly bend a valve taking the head off and back on? or even when timing it up?

 

This is common on GTI-6's where for no apparent reason after a rebuild you have a slightly bent valve that taps with incredible volume Most think tappets at first and at £200 a set they do nothing to cure the problem

Edited November 11, 2006 by dommorton

[PumaRacing 2]

Seems to be quieter especially at tick over but still does not sound healthy when driving it. I removed the rocker cover and tried to push the buckets but none seemed squidgey. There were 2 that were moving but I think I was pushing the valve down. I will persevere. Apparently the bucket only primes with oil when the valve is shut. I could have crap in the bucket stopping the one-way valve from shutting. Any ones opinions would be gratefully received.

 

I think it's more likely that running without oil has done some mechanical damage to the cam lobes or lifter surfaces. That would happen very quickly, seconds or minutes rather than hours. It should be apparent to the naked eye if you know what you're looking for but probably better to measure each lobe with a vernier and check each lifter against a straight edge.

 

As an aside, in the past I have successfully resurfaced those lifters on the grinder if the damage is not too deep. Less than 5 thou or so. Cheaper than new ones anyway.

[petert 587]

As an aside, in the past I have successfully resurfaced those lifters on the grinder if the damage is not too deep. Less than 5 thou or so. Cheaper than new ones anyway.

 

I resurface them by rubbing by hand in a figure 8 pattern on the side of a cam grinding wheel. I appreciate that not everyone has a large grinding wheel laying around however. Any flat surface will do however, such as glass with #60 wet and dry. The fig. 8 pattern limits the chance not grinding perpendicular. It takes approx. 2-3 minutes per lifter. If they haven't cleaned up in that time the damage is too deep.

 

Once you've resurfaced them and totally dismantled and cleaned the internals, they're usually right to go back into surface. As Puma said, much cheaper than new ones and the OE lifters are much better quality than aftermarket items. I have set of Piper hydraulic lifters here that lasted just 5000Km. They all failed on the top of the piston. Obviously a quality control issue. Interestingly, the mechanic who replaced them mistook big end noise for lifter noise! So the engine failed anyway.

 

I've also seen a full set of lifters replaced without fixing the cam lobes. Luckily I caught it in time and saved the new lifters.

 

Mi16 cams are very hard and if well looked after with quality oil will last a long time. Remember that the cam/bucket relationship is the most highly stressed part of the engine. Cheap oil, or no oil, will kill both items in a short time. You should also try using a zinc additive with your oil. Zinc has been removed recently from oil as it affects cat. convertors (apparently). The results is increased wear in soft cams (eg Pug 8V). Crane make an additive that can be used as an assembly lube.

http://www.cranecams.com/?show=browseParts...tNumber=99003-1

 

This is a good read:

http://www.micapeak.com/info/oiled.html

 

Basically, don't choose an oil without zinc (especially if you own an 8V).

Edited November 12, 2006 by petert

[jerseypug 1]

The cams and all the buckets look fine and none are squidgy. When I originally removed the head (the engine had been running sweet with no noises just the water pressurising) I turned all the buckets upside down and submerged them in oil until I refitted them in the correct order.

When I originally took the cams out, the cam carriers that are numbered 1 to 5 were in order 1-3-2-4-5 so I replaced them in the correct order as it looks like number 3 stops the cams from moving backward and forward.

Instantly as I started the engine the tapping noise started which I presumed was the tappets needing to pressurise. I had liberally oiled everything as I put it all back together.

I am going to remove the rocker cover again and have a good look at the cams and if I cant see anything obvious I will have to re surface the buckets and re prime them.

the big end shells are new and the oil pressure is very good.

[Higgy 0]

Sure its not injectors.

 

My mate is breaking a Skyline, and while we had the engine running all you could hear from that straight six was the injectors clicking. I personally think they sound very much like tappets.

 

Higgy.

[jerseypug 1]

much too loud to be the injectors.

removed the cams last night, no visible damage to the lobes or buckets. i measured the lobes and were all within .07mm of each other. tried to push the buckets down without the cams in the way and they all seem firm. might as well clean them out and re prime them and see if it helps. whats the best way of cleaning and re setting them?

[petert 587]

whats the best way of cleaning and re setting them?

 

whack them on a piece of wood until the piston assembly comes out. Sometimes this can be difficult if they're badly gummed up, but never impossible. Once removed from the bucket, the piston assembly can be further disassembled into three parts - check valve/piton, spring and body. Soak all four parts in a very strong alkaline degreaser overnight. I use tin cans, one for each bucket assembly, half filled with degreaser and agitate regularly.

 

When they're washed in water, dried and super clean, inspect for damage. At this point I dress the tops of the buckets as stated previously, then inspect and wash again. Then you're ready for assembly.

 

Fill the bucket with a few squirts of oil. Don't be concerned about over filling. Any excess will squirt out later. Then put a few drops in the piston body, along with the spring. Push the piston in, and at the same time, use something pointy/sharp to open the check valve, allowing any trapped air to expel. If done correctly, you should be able to still compress the piston approx. 1mm. It shouldn't be solid. This is called pre-load.

 

Then push the piston assembly back into the bucket. Any excess oil in the bucket will now squirt out. And that's it!

[jerseypug 1]

Cleaned out all the tappets and primed with oil, put the cams back in and was rotating the exhaust cam to align with the timing hole when I heard the noise. It is the same noise the torque wrench makes when it has hit the required torque. It happens just when the cam lobes are starting to push the buckets down on number 2 cylinder. I used my stethoscope to try and find out exactly where the noise is coming from but is very hart to pin point. It is either the buckets, cam or valve spring. I measured all the lobes on the cams and they were all very similar in size. (0.07mm) between them. I have rotated the bucket and it makes no difference. Could it be the bucket making the noise because it hasnt primed fully with oil? I suppose if I can push the bucket down with the cam lobe pointing up and it makes the noise, it is not the cam lobe or bucket surface. If it does not make the noise when I push it down I presume I have to change the cam and buckets and try again.

[dommorton 0]

My money is still on a slightly bent valve

[jerseypug 1]

It was the exhaust valve clipping the opposite inlet valve as they were slightly open.

I will try to put it together tonight and see if it is ok

[Guest Maikel205]

My MI16 has the same tappet noise, driving with it for over two years now. Replaced the tappets with no result. Few weeks ago I found out what I did wrong two years ago. Before placing a new cambelt you need to pin the camshaft pulleys. If you pin the inlet cam pulley, two valves (2nd cilinder from cambelt) are fully opened. After that I turned the exhaust pulley round to pin it. I turned too much, result is that two fully open inlets slightly touch with two fully open exhaust valves. This is a mistake I made and I think other people too, but I will never do it again.

 

The valves are only slightly bent, but enough to make a lot of noise. Performance wise, the engine does not suffer from it. This winter I'm going to replace the 4 valves, to get rid of the noise for ever.

[dommorton 0]

Same problem that's occured on many a GTI-6 engine too

[davev 1]

this is a kind of hijack but im hoping you lot are describing my problem.

 

ive got a loud tapping noise in the mornings(definatly not bearings) it comes and goes till the engine is nice and warm and seems to be getting worse as the days are getting colder.

 

best type effect is:

...t,t,t,ti,ti,,tic,tic,tick,tick,TICK,tick,tick,tic,tic,ti,ti,t,t,t.....

 

i got a feeling its a bucket though as i think i can hear a second one going slowly. so it looks like i got a nice job to do when i get a second car/next head.

 

is this the same as yours or is mine different?

 

dave.

[jerseypug 1]

this is a kind of hijack but im hoping you lot are describing my problem.

 

ive got a loud tapping noise in the mornings(definatly not bearings) it comes and goes till the engine is nice and warm and seems to be getting worse as the days are getting colder.

 

best type effect is:

...t,t,t,ti,ti,,tic,tic,tick,tick,TICK,tick,tick,tic,tic,ti,ti,t,t,t.....

 

i got a feeling its a bucket though as i think i can hear a second one going slowly. so it looks like i got a nice job to do when i get a second car/next head.

 

is this the same as yours or is mine different?

 

dave.

 

mine is a constant ticking, it sounds quite painfull when driven and never goes quiet. i have put it all back together now and will fire it up tomorrow as it is too late now and i am going to have to get the revs up to prime the buckets.

[jerseypug 1]

sounds exactly the same as before. i have been hopeing i would not have to remove the head again but looks like a new set of stretch bolts and another head gasket needs to be ordered. will it be obvious when i remove the head if the valves are bent?

[dommorton 0]

One only need be bent a very small amount to cause it to catch

 

Took a machine shop to spot it on my GTI-6's head

[jerseypug 1]

just done a compression test 180 174 175 183 does not seem to confirm a bent valve but does not rule it out either. i was hopeing that one reading would be wat out.

174 was the cylinder where the valves caught each other. i am going to take the head off this weekend to have a look. if it is a bent valve, is it likely the guide will need replacing as well?

[dommorton 0]

My 6 engine gave good compression too as the valve was closing but tight in the guide due to the bend in it. The piston was smacking it shut hence the tap.

 

I had guide done too as with the bent one running up and down it there was sure to be damage.

[pugrallye 0]

bent valve, they only have to be slightly squew to tick normally from a previous cambelt failure on gets missed or mistimed when changing belt or similar it only has to be slighty slighty bent (hence no performance loss as valve cannot rotate properly but still seats..under duress lol)

Edited November 26, 2006 by pugrallye