Mi16 Noisy Tappes

[floodys 4 1 Cars]

before i buy a set of hydroilic tappets, has anyone tried that stuff you can get from motor factors for quieten up tappets and if so is it worth trying a bottle?? if not, any idea how i can identify the rogue tappet!!!

[GLPoomobile 958]

Oil additives are a load of old cobblers and not worth using.

 

If you've got a sticky tappet then you'll need to remove it and clean it up. A search might reveal more on that, it's not something I've done myself although it's apparently very easy once you have the tappets out. There's also video guides on Youtube.

 

You can identify noises like this using the stephoscope method. I've got a cheapo mechanics stephoscope from a pound shop that I paid.....errrrmmmm......a pound for That works very well. Or you can just put the end of a screwdriver to the head and put your ear against the handle. Move the end around to find out where the sound is coming from. But as above, if it is a sticky tappet you'll need to get at 'em and identify which one/s are the problem. Might as well do all of them at the same time though I reckon.

[EdCherry 34 1 Cars]

PeterT has a good guide on his site for refurbing tappets.

[floodys 4 1 Cars]

doh!! done the whole lot already, i tapped them out and cleaned them etc, i reckon one is we;ll dead!! oh well, cams out ireckon and new one!!..or 2

[floodys 4 1 Cars]

i've noticed that the car smells a lot of petrol out the exhaust, if i have a dodgy tappet would it let unburnt fuel through? i also did a comp test and all came up the same, (i hopeing i didnt have a dodgy valve???) i've now got the rocker cover off so ican see the cams and tappets, anything i can do/see to see if i have a dodgy tappet??

[DrSarty 90 1 Cars]

Fuel goes nowhere near the tappets.

 

Remember the valves effectively point straight down, and fuel and air comes in from the side meeting the stem of the valve (and no higher) in the port to travel down into the combustion chamber when the valve opens.

 

The tappets pretty much sit in oil, so to suggest this would mean petrol was getting into the oil as well. This would be bad as it would thin the oil.

 

Likewise, for unburnt fuel to come out of the exhaust, it would be going out at 90deg to the valve but on the opposite side of the head from the inlet, again nowhere near the tappets. What's your CO reading? Is it mega rich which would explain that smell?

 

If all the comp test results are the same, this seems good. You haven't posted the results, but it does show that all of the cylinders are sealing equally well or equally badly depending on your point of view.

 

You cannot see if a tappet is dodgy, especially not whilst it's still in the head.

 

They tap because either they are blocked or knackered inside (or not getting enough oil), or they've worn down enough (have a crater in them that can't be re-faced) to not take up the valve clearance for you. That's how they work; they're hydraulic.

 

Tapping from a head comes from knackered tappets or a bent valve usually. Those are the most common sources.

 

I think you should go back to square one with us and tell us exactly what you did with this head when it was in pieces. Do you know all of the valves are true?

 

SO in summary, tell us everything:

* what's the CO reading - is it running rich?

* what did you do to the head - i.e. valve and tappet history please?

* what were the comp test results - i.e. figures?

Edited August 4, 2009 by DrSarty

[kyepan 291]

It would depend if it's a single lifter that's stuck and isn't pumping up, or all of the lifters.

 

What oil are you using, lighter weight oils some times allow cars with hydraulic tappets to sound a bit noisier.... especially when warm. My mazda mx5 uses 5-40w and it rattles when warm as the clearances are not quite maintained by the warm oil..

 

using thicker oils can quieten it up.. although you should really use the correct oil.

 

mi should use 15-40 semi synthetic, 10-40 might sound a bit rattly.

 

Also if your oil is due for a change, s*it in the oil might make a single lifter may stick, this sounds more like an old ford fiesta when the tappets need adjusting, and will sometimes clear when you drive off up the road.

 

Mine did this a while back, and i did two oil changes in fairly quick sucsession due to a sump swap, this cleared it up nicely.

[floodys 4 1 Cars]

ok, basically the comp test readings were all around 12 bar/175psi, its got 10/40 semi oil, the crazy thing with the co is that its rich, but opnly at 2.4ish,not what i would call rich. with the head i took cams out, took out all the tappets and knocked them out, cleaned soaked them in brake cleaner and re-built them as per the tappet thread somewhere on here i think, then put them back in the head the same place each one came out.

 

i understand the "fuel go's no where near tappets" what i ment to say and prob didnt explain properly was that if the tappet was stuck open, could the valve be stuck open very slightly thus fuel coming into chamber whilst exhaust valve open??

 

when the head was off i also had a good look at the face of the head and from what i could see the valves were all seated when cams were out, in heinsight i should have put a load of compressed air down the ports to see if i had a leak/bent valve.