Can anyone advise me how much is a fair price to pay for Valve Guide repairs on a 3lt 2nd Gen Verada, she puffs out a little smoke on start up, and after running for a little while.
My Mech. says it would be a major job, so any help would be much appreciated.

a guess

how many km has this motor done ?

to do all the valve guides on heads should be about $1000

the (blocks)edit heads have to be heated and refitted with new valve guides

you could just have the valve stem seals replaced to see if that reduces the smoke
that way the heads dont have to come off
the seals can be replaced quite quickly

Agree with Magna Buff. Ask your mechanic if he can change the valve stem seals without removing the heads ie: compressed air line fitting in the spark plug hole & compressed air to hold the valve shut whilst using a spring compressor to compress the springs in situ.

To change the guides you do not heat the block you heat the heads, the guides are in the heads not the block, typo I am sure

The stem seals are very well known on the second gens for going hard and then you get that puff

These are not hard to do on car, have done more sets than I have had hot meals lol

These are not hard to do on car, have done more sets than I have had hot meals lol

Time for a new partner.

Stupid question, what are valve guides?

Valve guides are the part of the head that the valve stems run up and down in as the valves open and close. Once the valve guides are machined the valve seats are machined to match the guides so as to ensure correct alignment of the valve sealing face to the head. On cast iron heads they are usually machined into the head during manufacture. On aluminium heads they are an insert which is fitted into the head during manufacture therefore allowing the valve stem to run up and down in a grade of material more compatible to the valve than the aluminium cylinder head material. In short-replacing valve guides in an aluminium head = heads off, guides replaced & reamed as required, valve seats re-machined / re aligned to new guides, valves with worn stems replaced, valve stem seals replaced etc = approx $1000.00


Cheers

Yep, basically whay Magna diver has said....

if your heads are a lump of softish alloy, and your valves are fairly hard metal to withstand heat and compression/detonation - it makes sense that the hard thin rod which is the valve "stem" would chew through the alloy as valves move up and down a zillion times every time you make a trip to the shops for milk.

The valve GUIDE is a tube of harder metal let into the soft alloy of the head, so that valve stem has something durable to rub against. On the "outside" end of the valve guide (ie: away from the combustion chamber) the Valve Stem Seals are a flexible material pressing on the thin rod Valve Stem and also sealing against the Valve Guide - the idea being to keep oil from running excessively down the lengthof the valve stem and being burnt in combustion chamber leading to smokey exhaust.

Now if the Valve GUIDES (the tube of harder metal let into the softish alloy head, remember) if these guides are worn, they let the thin valve stem (like a bit of rod) have too much slop in the guide....... may even "wobble" - so if guides are worn, not even the most-super-duper-brand-new set of Valve Stem Seals will cope with the excessive movement. A decent and honest mechanic will assess whether the guides are worn beyond the ability of new seals to cope.

Probably best to have a look for "how stuff works" or Wiki, or Car Bibles etc to really see a simple diagram to understand what we are saying.

So wouldn't it be cheaper to get new heads

Bought a pair of Advance 6G74 LPG heads from a U pull it wrecker for $100.00 complete with cams & sprockets, rocker covers and rocker assembly etc. Servicing of the heads ie: bath/clean up, check guides, machine head gasket surface, machine valve seats, crack test head etc cost $280.00. Cylinder head valve regrind gasket set (known as VRS set) from memory was $350.00. So the approximate price for some one doing it at home is say $750.00-800.00. Don't forget to allow for growth work like say: you checked the water pump and found the pulley was loose and wobbly on the bearings ie new pump required or the cam belt, cam tensioner pulley, cam idler pulley, cam tensioner, cam oils seals or crank oil seal had problems and needed replacing. Cost of water pump is ??? depends where you buy it from. Cost of dayco cam belt kit with tensioner & tensioner pulley, idler pulley x 1, cam oil seals x 2 and crank oil seal x 1 = $315.00

Regards

So wouldn't it be cheaper to get new heads

Probably not, unless you find good heads at a good price (veering dangerously close to swear filter territory with that statement). NEW heads (ie: brand-spankers, genuine parts new) = sell your children rates, I would guess. Don't suppose Mitsi Clearance is overflowing with these?

If the valve guides really are worn (ie: you're not being ripped-off and told they are changing guides when all they plan to do is pop new valve stem seals in), then there is a fair bit of time and work as described to get old valve guides out and new ones in - heating the heads etc.

If you stumbled on heads in good condition with no defects and little work req'd, it might be an option, and could cut labour cost a fair bit. Could ring spares counter, some wreckers, Mitsi Clearance to check prices, I suppose.

Lets put aside the fact that this engine being spoken about prob is high mileage, doing the heads will only result in the bottom end letting go. Stem seals are find on most engines unless they have been run for years on Gas and thus have more seat and guide wear.

Just get the stem seals done, the parts with rocker cover gaskets, end caps and seals should not be over 100 bucks, the labour, allow 4 hours max

Car has done 230k, not very well looked after, need to work out weather to keep it or sell. Paint is shot, but it runs so smooth and interior is great now that Ive renewed the roof lining. how long can I expect the motor to perform well with out too much exesive smoke, at the moment it only puffs at startup, and only for a second, and when she's at idle, and then only a little for a very short time. I have also had the brakes done, with a service.
Any help is greatly appreciated.

Lets put aside the fact that this engine being spoken about prob is high mileage, doing the heads will only result in the bottom end letting go. Stem seals are find on most engines unless they have been run for years on Gas and thus have more seat and guide wear.

Just get the stem seals done, the parts with rocker cover gaskets, end caps and seals should not be over 100 bucks, the labour, allow 4 hours max

Explain how that works? :confused:
Put re-co heads on mine and bottom end held up fine after 230K, Cylinder bores still looked like new!

It is a common issue when you do heads that the bottom end can start to cause smoke etc as the new top end, if done correctly, will be a perfect seal the worn bottom end parts (rings etc) can then allow more than usual blow by

Generally a bore can look 100% but it is the rings that suffer