Page 1 of 1

Engine Problem

Posted: Sat Feb 21, 2009 10:39 am
by hyzook
I have posted this here as its general mechanical not just suzuki,
The engine in question is a 95 Vitara G16B 1.6lt 16 valve MPI.
I have owned the engine for 10yrs and got it with 40000km on it and it has not missed a beat ever. Recently the engine had 130000km on it and was starting to use a little oil every few months so as I had it out I sent it to the mechanics for a rebuild to freshen it up.
Below is from my members thread but I am looking for suggestions on the possible cause.


After the engine went in it seemed to be blowing a little smoke, after some consecutive hard braking due to testing it billowed out enough smoke to make think the fire brigade would turn up. This smoke cleared after a few minutes and some hard revving but it has continued to use oil, when I let it idle for a while it will blow smoke and I get a black dry substance deposited on the ground from the exhaust. We decided leave it until I had some kilometres on it but it has not improved therefore I have got the front end off and am about to remove the motor to see what has happened. So far in the removal I have noticed the exhaust manifold gasket is quite wet with oil, the plugs are all black and although it seems to be running rich the fuel economy had has improved by almost a litre per hundred. The mechanic is thinking the oil rings are not doing their job but we are also going to check the head which has been reconditioned and had new valve stems and seals.

RESULTS OF STRIPPING

Turns out aftermarket valve stem seals were used, genuine are now fitted and the engine is back together and it’s been back on the road for a few days and it seems to be going better.
While it was apart we removed one of the pistons and checked the rings, there was no carbon build up around the ring (which I was told indicates the rings are sealing) the bores seem to have run in OK and there was no sign of glazing.

It’s now done around 150km since the new valve stem seals were installed and it’s used another litre of oil. Yesterday I let it idle and after 5 min once again black soot was coming out the exhaust and if I revved it black sooty smoke came out followed by blue/ white smoke. It doesn’t seem to smoke when driving and as long as I don’t leave it idling it is fine.

Since the engine was done power has increased and fuel consumption has improved, it also revs harder and keeps pulling all the way to 6500rpm (used to drop off at 5500rpm). The mechanic that rebuilt it has since closed shop and lives a fair way away which doesn’t help, I have known him a long time and he is honouring the work and has suggested letting it get more KM on it before we strip it again (although as he said last night if it used a litre in 150km then it doesn’t look good).

My concern is I don’t want to strip again and have another guess at what the problem is, I would like to try and sort it once and for all. When it was out we found a heap of oil on the pistons and oil built up at the bottom of each valve guide indicating stem seals, however when they (engine machining mob) fit the genuine seals they say they didn’t feel much tighter??
I am confused as no shortcuts were taken and we checked it all twice over before reassembling.
I think I need to find someone who is experienced in these engines and run the problem past them to get there opinion. Sometimes the simple things are overlooked and maybe we haven’t checked all the possible reasons for the problem but are assuming the worst.

Help any one :?: :?: :?:

Posted: Sat Feb 21, 2009 11:31 am
by nicbeer
oil pressure and compression all good?

any blowby and also have u done oil change at all?

Posted: Sat Feb 21, 2009 12:48 pm
by simkell
was the head crack tested? was the head machined?
however it sounds as oil leaking past the valves at idle.

Posted: Sat Feb 21, 2009 1:01 pm
by Guy
Valve guides would be my guess.
If the guides are loose the seals wount do much.

If you pull it all down again your best bet would be to check all the tollerances etc, not guess.
There will be something measureable you can fix.

Posted: Sat Feb 21, 2009 6:50 pm
by hyzook
Compression was 180 at each cylinder but have not checked oil pressure, it's had a few oil changes. The head was machined (don't know about crack tested?) The head gasket looked fine on removal. The inlet guides were done initialy and the second time they did the outlet guides as well to be sure, funnily they also replaced a valve the second time round saying it was slightly bent.
I was thinking oil pressure maybe but its not leaking any oil. The PVC valve seems to be operating correctly which make me think that while its in vacumme there is no oil but when idle not enough vacuume is there and causing the oil to be forced past the seals.

The thing is it's not one or two pistons only, and like wise with the valves its all of them, for this to be the case I am thinking maybe oil coming past the valves is the result of a seperate problem.

Thanks for suggestions I will try anything at this stage...............

Posted: Sun Feb 22, 2009 9:33 am
by roblrc
How many k's since rebuild? not unusual for a fresh engine to blow some smoke and use a little oil till run in properly. could be more than 5000klm. Also you have disturbed it when the head was off by pulling the piston this needs to bed again. Dont forget the oil in the exhaust may take a while to clean/burn out. also are you using a full synthetic oil if so change back to a mineral oil have done oil changes for customers that requested that syn thetic be used after someone telling them that its better and car developed high consumption and smoke changed back to older style oil and after a short period all good. just some tips

Posted: Sun Feb 22, 2009 10:04 am
by thehanko
roblrc wrote:How many k's since rebuild? not unusual for a fresh engine to blow some smoke and use a little oil till run in properly. could be more than 5000klm. Also you have disturbed it when the head was off by pulling the piston this needs to bed again. Dont forget the oil in the exhaust may take a while to clean/burn out. also are you using a full synthetic oil if so change back to a mineral oil have done oil changes for customers that requested that syn thetic be used after someone telling them that its better and car developed high consumption and smoke changed back to older style oil and after a short period all good. just some tips
yeah synthetic killed my bike engine after it was rebuilt. started blowing smoke like that.