engine people..take a look at this inlet valve

[pidgeon chit welder]

if the heads off it never hurts to replace the guides at the same time.....

Agreed but guessing if the block and bores etc are OK is a mighty expensive and risky venture to under take if you have not tested it and just topped it ..

But it is said that experience .... is expensive

 

[brookie456]

It's a type of valve guide liner I think.

Phosphor bronze liner, drill to size, fit etc. and ball broach to suit valve stem - advantage is you can compensate to a certain degree for valve stem wear, and they're rifled, aiding lubrication along the stem. Thing being when you have steel guides in an ally head for a long time, they tend to drag out material when being removed - last thing you need is a guide moving - used this lots on old British bikes etc. at work. Watch out for semi-finished (ie require reaming-cow of a job) or oversized on the guide outer diameter - they don't always list it On an old VW, should be o.k.

 

[brookie456]

And check your breather pipes from crankcase, head etc. - if you have minimal guide wear etc, the most probable cause of the gunge, and check that the restrictors are still intact.

 

[pedrobedro]

In an old Polo I'd clean it and put it back together with some new seals. How long are you going to keep it and did it use a lot of oil before ?

 

[steveo3002]

i plan to keep it a while..but these engines are cheap to pick up so i wont spend ££££ making it better than new

i bought it out the car , havent ran it or done compression tests , the exh manifold was fairly dark grey /black soot but not oiled up

for the record i have a few similar vw's with way over 100k , none use any oil to speak off

 

[tigler]

I really don't think any modern engine is intended to burn oil, 2 main reasons, 1/ emissions, 2/ it would poison the cat.

 

[Pete.]

Don't like cats anyway - and they don't like me!

I'm firmly in the 'clean it, lap the valves, fit new seals' camp. No way I'd be putting guides in an old polo engine unless I planned to keep it forever.

 

[steveo3002]

while i dont plan to keep it forever , i do like the car and dont want to be pulling the head off again in 6 months

although i spose i could then refurb the other head at my leisure and fit that if the other burns oil

 

[mike os]

TBH in those circumstances I would fit seals & see... new head kit is what ? £50? if it needs doing....

 

[steveo3002]

yeah less than that for a head set

one other question..the valve faces have cleaned up like new with a drill and bit of emery cloth ..all excpet one that has some slight pitting

a, is the pitting anything to worry about

b, could i hit it with something a bit fiercer to try and smooth it out

 

[Wayne.]

not really if lapping doesn't take care of it then you could have it recut if the pitting is minor lapping should sort it, but one new valve ain't going to break the bank. if you put it back as is and do a leak down test on that cyclinder i can assure you it wont seal.if your going to keep the car for a while theres only one way to do the job and thats the right way i dont like having to do a job twice

 

[mike os]

drill is not the best way tbh if there is wear in the stems it can oval the seats... by hand with a plunger/sticker.

depends on the depth of the pitting I would continue lapping if it looks like it is shallow ot a new seat if not.

 

[steveo3002]

no , youve not understood

i span the vavle in a drill to hold some emery on the the face , the bit that faces the piston

that face that faces the piston has some minor pitting ...can i hit it a bit harder to remove the pits

the lapping has gone fine with a stick and paste

 

[Wayne.]

you can do it with a drill but not from the valve spring side use a ezi lap has a sucker on it and sticks to the valve face just the same as the wood one that you use by hand.hand lapping valves in is a pain in the ****

 

[Wayne.]

no , youve not understood

i span the vavle in a drill to hold some emery on the the face , the bit that faces the piston

that face that faces the piston has some minor pitting ...can i hit it a bit harder to remove the pits

the lapping has gone fine with a stick and paste

i no what you mean it has to be cut to a certain angle or it wont seal,very difficult if not impossible to replicate the angle by hand

 

[the snooper]

inlet valves are worse when it comes to the oil seals due to the vacuum drawing oil down the stem.
im also guessing that engine has been laid on its side at some point as there seems to be a pattern of oil across the head and valves which may account for the valves being wet

 

[ratmanrover]

Just up my street.

Its what i do as a job is fix heads. (engine ones that is). It could be numerous things but basically its burning oil. Valve stem could be worn, guides could be worn, stem seals could be knackered, piston rings, cylinder bore could be worn. turbo? could be leaking a bit (if its a diesel that is). Every thing needs to be measured and checked to do a propper job. I have seen worse though.
Hope this helps!

 

[pidgeon chit welder]

I really don't think any modern engine is intended to burn oil, 2 main reasons, 1/ emissions, 2/ it would poison the cat.

Re the VW ,
I thought that till I found that I was having to top up the engine oil on our Bora far more than any other engine .. the service schedule allowed for new oil every 20 K when the records were checked we were using nearly 8 litres of oil extra.

On checking with local VW agent was told this was considered OK they are designed to use / burn the oil and yes the engine and exhaust are clean .

That's why I was nonplussed when I saw the rich dark chocolate of the valves and the condition of the spark plugs.

 

[steveo3002]

.

On checking with local VW agent was told this was considered OK they are designed to use / burn the oil and yes the engine and exhaust are clean .

That's why I was nonplussed when I saw the rich dark chocolate of the valves and the condition of the spark plugs.

thats dealer lies for you ...they cover thier behinds saying up to 1ltr per 1000miles is within spec

none of mine use a cup full between services

 

[mike os]

bloody hell.... my passat diesel uses exactly none between services

as does my renault vivaro 2l diesel.......