Page 1 of 2

Blue smoke

Posted: Thu Aug 15, 2019 9:55 pm
by Shafy8807
Hey guys I've recently got a 5g 2.2 and it's very intermittent on vtec and puffin blue smoke when you accelerate. The car is currently off the road I've done a compression test and that's all good testing the oil pressure soon but if its not that would anyone be able to point me in the right direction please or if anyones had this before and managed to sort it I'm not 100%clued up on mechanical things but have a mechanic mate helping me out if it comes down to it and I do need to buy a new engiene how much should I be looking at paying?

Blue smoke

Posted: Thu Aug 15, 2019 10:30 pm
by Scott560
When you say intermittent on VTEC, describe what happens?

VTEC will only be on at very high throttle over the 5200rpm vtec point. You should hear it kick in on a full throttle pull.

Is it just the vtec that is bad, or is the car faultering at any other point?

If you have low oil pressure, the ecu will cut off vtec, but you will get an engine management light come on. Is the light on , and does the engine light work when you turn on the ignition? Someone might have removed the bulb.

If you do have low oil pressure in vtec, then there isn't much you can do about it other than rebuild, or easier still, replace the engine. Low oil pressure means bad thinsg have happened, or will happen soon. Assuming you have enough oil on the dipstick, and you've got the right grade oil in there, and replaced the filter, there isnt much you can do. You could check the vtec solenoid gasket/screen, but i'm not sure if the sensor is before or after mesh. Either way if its blocked or clogged, then bad things have happened.

If the vtec is kicking in and out, but the oil pressure isn't the problem (eg no engine light) then it could just be the vtec solenoid wire. Check it looks ok and is making a good connection. if you are still no further forward, an assistant could run a jumper wire from the solenoid direct to 12v, this will physically engage vtec. Only do this in the higher rev range, see if it clears up the issue.

Blue smoke on acceleration is obviously burning oil. If its not on de-acceleration, its less likely to be valve guide seals, and more likely to be bottom end. I don't know enough about the breather setup but if its breathing smoke that visible, somethings nackered.

Blue smoke

Posted: Thu Aug 15, 2019 10:40 pm
by Shafy8807
When I brought the car as was driving it home the oil light would start to flicker when stopping at traffic lights but then as soon as I was driving it went off the oil was the 1st thing i checked and was fine on oil my mate did say maybe change the oil but do the test and stuff 1st just to save wasting money on oil if it was the engiene. And intermittent as it just decides as and when it wants to work no other way to explain it my friend works for a garage so asked him to take it to work just to see what he thought and when he came back he said the same thing vtec kicked in all of about 2 times was sporadic like I said he is helping me with it all as he knows alot more then me I was just hoping someone else could shed some light on it and point us in the right direction he has said he thinks it will probably be a new engiene but obviously trying to save me some money has offered to do all the test and everything else 1st

Blue smoke

Posted: Thu Aug 15, 2019 11:07 pm
by Scott560
Oil light flickering at idle is a classic sign it's buggered.

The oil pump is either gone, or bearings worn out so bleeding out all your pressure. Any repair is likely to be more than buying either a known engine or probably just buy another prelude...

Either way new engine time...

Blue smoke

Posted: Mon Aug 19, 2019 1:05 pm
by vanzep
id clean the up vtec solenoid first and check the gasket (rubber surround with metal mesh filter)
its just a couple of bolts and can be done in minutes with a good spray of carb cleaner
remember wheeler dealers when they had the s2000 that had a full engine rebuild but never worked properly due to the vtec solenoid filter being blocked. ed china got lucky and sorted it out with a clean and new gasket for about £20...fingers crossed.
mind u the flickering oil light doesnt sound good......

Blue smoke

Posted: Mon Aug 19, 2019 3:56 pm
by Scott560
Nah the flickering oil pressure light is the main oil pressure sensor in the block, before you get to the VTEC sensing oil pressure switch in the head.

If the main oil pressure light is flickering, then you have no chance of VTEC, and your engine (or oil pump) is already shot.

The workshop manual (for the b series at least) has a good diagram of internal oil flow, so you would be able to work out if blockages in certain places would cause you trouble.

remember VTEC will also not engage until the car has warmed up to a certain extent.

Blue smoke

Posted: Mon Aug 19, 2019 8:53 pm
by vanzep
yeah your probably right...the only other thing i can think of is to check the oil pick up isnt blocked - small chance if someone has used silicone sealant on the sump or rocker etc can become detatched and cause problems.

Blue smoke

Posted: Tue Aug 20, 2019 3:05 am
by newkid
Been there done it. Oil light flickering will be due to the oil pump failing. Full rebuild or replace for a known working engine. Keep driving an you'll more than likely spin a shell.

Blue smoke

Posted: Tue Aug 20, 2019 3:27 am
by JEBB4
Start by pulling the sump off and checking the pickup isn’t blocked before getting too carried away, a sign will be excess carbon build up inside your rocker cover and just generally jobby condition inside the engine..

Bought a civic with same thing cleaned pickup, was fine for months then same thing again, cleaned it again and never came back.. that was a very bad case...

It’s due to a lack of oil changes/maintenance or wrong oil used frequently, seen it so many times over here..

There is a chance that it has done major damage to oil pump, cams, cylinders, rings, big ends and mains but you have nothing to lose by just checking the oil pick up and cleaning it and the sump out thoroughly and see if it fixes it... as mentioned above though if it’s got to that point chances are the VTEC solenoid and gasket/filter is blocked so will require replacing or if your luck a good clean..

ALSO smoke out the back due to oil burning could be as simple as a blocked or failed PCV valve or could be more excessive such as piston ring failure or valve stem seals..
Start with the basics.. valve stem seals can be done without removing the cylinder head with the correct tools but is fiddley.. rings will require head off and sump off but not engine removal... I’ve done both of you get to that point and need guidance I’m happy to help :)


Don’t condemn the engine yet give it a chance.. hope that helps :)

Blue smoke

Posted: Tue Aug 20, 2019 7:27 am
by Shafy8807
Cheers guys much appreciated I will show my mate what you've all put go from there the car wont start any more now for some reason after we did the compression it just tunrd over theres no spark had another mechanic aswell as my mate come to have a look and there both pretty stumped as to why it wont start he did say it's very rare but when we did the compression he thinks the dizzy might have been damaged before and its broke somehow so hes getting a think he called it a (touch light ) so as soon as we can get it started again I'll start looking at the stuff you guys have said I have brought it as a project car so it will be off the road for a while rear arches was ment to be the 1st thing we were doing until all this with the engeine haha