to flush or not to flush

[CreelReaper]

Hey all,

The '93 3.0l Paj is due for an engine oil and filter change. I've had it now for 2 1/2 years and when bought I renewed the engine oil with Castrol Magnetec 10W40. The motor has done 280,000 odd kms.

The last few months it has been blowing a bit of smoke (yes I know it is a common Pajero 'fault" and has started using a bit of oil. Noticeable mostly after idling for long periods in brisvegas' wonderful traffic jams and when decelerating.

Is it worth giving the engine a flush prior to renewing the filter and oil??? I was thinking of using a thicker oil also.

What do you guys use in your 4x4 petrol v6 engines???? Any recommendations and thoughts would be appreciated.

Cheers

Shane

[Benny01]

a flush wont dont anything at all to stop smoke. really the olny thing would be to go to a 20/50. anything thicker might play up with your lifters

[FNQCairns]

Be a little careful of oils that have a big gap between the two numbers in it's weight, generically they are rubbish for the mass marketed to the 'crowd'. Synthetics can pull it off as can high quality semi synth but plain old dino.....well oils ain't oils.

Also the science behind the first weight contrary to popular belief only applies at below 0deg C, 5w oil at 20degc can be heavier than a 15w at 20deg C....but at -10 the 5 will be the most free flowing.

What about buying a $30 compression gauge and testing each cylinder, from here you can then make a decision to try a few cheap de-cokeing remedies if it reads as stuck rings or throw a too thick oil in if one (or more) cylinders are too low.

Usually oils thicker than 40 do nothing in a healthy engine except try and hurt it.


cheers fnq

[Benny01]

its a 280,000km pajero. well into bonus years. coles brand oil will do it. nothing is gonna help stop it blowing smoke.

[White Pointer]

G'day,

It's time for an engine pull down. If you do it now it will be less expensive than when you have rooted sleeves and a sump full of unburned fuel. It could be fairly simple at this stage, just valves and guides. But get the sump dropped and the bottom end checked and pull a piston down off each bank to check carbon on the rings and pitting on top of the pistons.

Its a good car. Don't wreck it labouring in traffic. If you can't afford the rebuild right now park it and save like hell.

White Pointer

[nigelr]

Won't hurt to give it a gentle flush, worth a try, nothing to lose at this stage.
Stick with the oil you have been using, or maybe a japanese-diesel-specific 15W-40, definitely replace oil and air filters.
Try and take the vehicle for a LONG (several hundered ks if possible) drive afterwards.
If you are lucky you may burn off some carbon and unstick your rings.
I have used this exact method with some success to rehabilitate my 1HZ Lancruiser, but it was blowing blue smoke on acceleration, indicating worn or stuck rings. The vehicle had the same use pattern you describe before I bought it. I only use it for longer trips now, which she loves. Anything else I use a petrol engined vehicle. Slow city driving and prolonged idling are hard on a diesel, IMO.
Are you blowing blue (burning oil) or black (excessive fuel) smoke?
Blue smoke as you describe may well be due to valve stem seals on the way out.
Black smoke would be more indicative of faulty injectors, or a worn fuel pump.
Good advice from FNQ and WP, IMO.
Cheers and good luck.

[GBC]

It's a petrol motor. I don't think diesel oil is the best thing for it.

[nigelr]

Oops, how embarrasing!
Thanks for the heads up GBC!
Shane, please ignore my post! Don't know what made me assume it was a diesel, perhaps GWs' reference to fuel in the sump, more likely just native stupidity though I'd imagine!
For what it's worth I have read on 4wd forums of people with petrol engines both flushing there engines and using diesel oil, with its' higher detergent levels, to clean up their motors.
Certainly never done it myself though, but would be prepared to give it a go on the old holden red motor in the Landy......could only do it good
Cheers.

[CreelReaper]

Cheers and many thanks for your replies guys,

Compression was checked about 3 months ago and each cylinder was down about 10% of recommended. The spark plugs were replaced last month and only No. 6 plug showed any evidence of unburned fuel. The rest were a healthy colour with a slight carbon buildup.

Just thought I'd learn a bit about what others would do before I took the plunge..........Yeah I know the oil change won't stop the smoke but a thicker viscosity oil I thought might slow the burning down.

With the flush I did think it may loosen up the rings and freshen the seals a bit and maybe slow down the oil passing the seals. Tommy tappet likes to dance occasionally too so I also thought the flush might clear out some of the oil galleries in the top end.

Although I can remember a mate doing this with I think redex many years ago on his old Torana and apart from creating the biggest smoke screen for miles around all he achieved was to increase his oil loss ten fold (presumably by removing the old gunge which in itself was acting like a 'seal'

I have used some of those 'stop smoke' products you can buy 20 odd years ago with not much success. Are they any better today and would you guys recommend or have you used this type of product with any success??

Also thinking of putting an injector cleaner through it too. I only use the 'WW' higher octane unleaded petrol because it improves my economy drastrically and seems to burn fuel much more efficiently. Would it be worth the cleaner????

Cheers

Shane

[White Pointer]

Cheers and many thanks for your replies guys,

Compression was checked about 3 months ago and each cylinder was down about 10% of recommended. The spark plugs were replaced last month and only No. 6 plug showed any evidence of unburned fuel. The rest were a healthy colour with a slight carbon buildup.

Just thought I'd learn a bit about what others would do before I took the plunge..........Yeah I know the oil change won't stop the smoke but a thicker viscosity oil I thought might slow the burning down.

With the flush I did think it may loosen up the rings and freshen the seals a bit and maybe slow down the oil passing the seals. Tommy tappet likes to dance occasionally too so I also thought the flush might clear out some of the oil galleries in the top end.

Although I can remember a mate doing this with I think redex many years ago on his old Torana and apart from creating the biggest smoke screen for miles around all he achieved was to increase his oil loss ten fold (presumably by removing the old gunge which in itself was acting like a 'seal'

I have used some of those 'stop smoke' products you can buy 20 odd years ago with not much success. Are they any better today and would you guys recommend or have you used this type of product with any success??

Also thinking of putting an injector cleaner through it too. I only use the 'WW' higher octane unleaded petrol because it improves my economy drastrically and seems to burn fuel much more efficiently. Would it be worth the cleaner????

Cheers

Shane

G'day,

Thanks for the additional info. It's pull down time. Tappet clatter says so. Do it before you have collateral damage.

Regards,

White Pointer

[Benny01]

all tappet clatter says is that the tappets are either stuffed or blocked

[far western dan]

i have a 97 3 lt pajero and the father in law had one about your vintage the tappet noise while not good is not the biggest problem does it do it all the time or just after a long run time and does it happen with the new oil my i have changed to a 15 / 40 oil and change oil and filter every 5000 kms and the tappet noise has disappeared only reapeers if i leave the oil change longer then 6-7 thousand. should say all my kms are long distance as i live in the top corner of nsw

[BigE]

Try a 10w-30w and add some morey's (from S/C or repco) good stuff.

BigE

[White Pointer]

i have a 97 3 lt pajero and the father in law had one about your vintage the tappet noise while not good is not the biggest problem does it do it all the time or just after a long run time and does it happen with the new oil my i have changed to a 15 / 40 oil and change oil and filter every 5000 kms and the tappet noise has disappeared only reapeers if i leave the oil change longer then 6-7 thousand. should say all my kms are long distance as i live in the top corner of nsw

G'day,

Nope! New thick oil can disguise the problem for a little while but by 1997 these engines could sustain FM oils for 15,000km.

Like I said, overhaul the top end, inspect the crank, draw two pistons to inspect and all will be revealed. A good mechanic will look at plugs for witness marks of over oiling and at the pistons drawn for evidence of oil residue or overheating.

White Pointer

[PADDLES]

hi shane, all the above advice is good stuff but don't lose sight of the fact it's a 15 year old vehicle with almost 300ks on it. my personal call is that unless you are really attached to it, or you require a high degree of reliability (planning a run across the simpson desert) then i'd use a relatively cheap oil and change it regularly, minimise any spending on it and run the little f$$ker into the ground, then make your decision on the motor when it's a smouldering heap. basic economics will tell you that there's no point spending thousands on a car that's possibly only worth between $5k to $10k unless you absolutely have to. best of luck with your decision mate, i've had to make this decision before and was sucked into spending the money and look back now at what a fool i was.