Rebel Rev

I have 3 things about my 88 that I can't figure out and haven't worried about because the car generally goes well. But maybe I should find out just in case something serious is going on.

1. Ever since I got the car, if I put my foot down when driving in the city at around 35 mph or slower I get noise from the motor... you could call it a clicking sound... doesn't do it at a higher speed when I put the pedal down.

2. For as long as I have had the car, if I lift up the hood and start it I sometimes can see a vapour or light smoke come up from the right hand side of the motor near the firewall. It only lasts a few seconds.

3. Recently, I have notice a very slight 'putt putt' sound coming at of the right exhaust when I go to the back of the car and have a listen when the car is in idle. It doesn't do it all the time... probably one 'putt putt' every 60 seconds.

The car idles perfectly and since I bought it over a year ago have driven it a lot without any major problems... even driven it interstate twice. Each round trip was about 800 miles.

The car has done 95,000 miles. I was told just after the I bought the car that the valve seals needed replacing and it does blow some smoke on start up.

Any comment of what may be going on would be much appreciated.

BOOT77

1 prob spark knock

2 prob oil leak and it's burning off

3 no clue, maybe your mufflers falling apart inside. I just had one side fall off my 86 and cut the other off, both orig and when I picked up one big chunks inside were rattling around.

Rebel Rev

Thanks for that...

1. So with a spark knock, what can I do about that... I have put new spark plugs in 8 months ago but that didn't stop it...

2. It does it instantly on start up so everything is cold... like a puff of vapour or smoke... I get out of the car to start it up so I am looking down at where it is coming from but haven't been able to pin point where it's coming from.

2. Yes, one of my exhaust pipes dropped down on the weekend at the back after a bracket snapped off, I reckon they have been on a long time... The previous owner took off the 2 back mufflers, leaving the 2 at the front and 1 in the centre... I think they are smog stuff.

Rebel Rev

[QUOTE=Rebel Rev;1587408603]Thanks for that...

Should be 3...

3. Yes, one of my exhaust pipes dropped down on the weekend at the back after a bracket snapped off, I reckon they have been on a long time... The previous owner took off the 2 back mufflers, leaving the 2 at the front and 1 in the centre... I think they are smog stuff.

AGENT 86

You may want to have a look at the EGR tube, from exhaust manifold to intake manifold.
May have a leak at either end.

Rebel Rev

Thanks... will look at that in the morning.

BOOT77

Spark knock could be many things, I'd check for vac leaks, mine had one when I got the car and it was the egr tube into the intake and that could be your smoke too! When you said right side I figured drivers, if it's passenger side could vary well be egr like Agent 86 said. Also assumed you meant when just opening the hood and I know from my leaking valve covers I would see some smoke rise from the hot engine after I opened the hood.

edit: nm I see your an asussie and my driver pass is diff.

rocco16

1. Detonation. Are you running premium fuel?

2. Coolant leak evaporating .

3. Missfire.

GKK

When was the last full tune up?...

Check the ignition timing, should be 6* BTC. Are you using 91 octane or higher?...

wydopnthrtl

1. Spark knock.... Small vacuum leak, too low of octane, Too much timing (chip?), excessive carbon in combustion chamber, plug wires cross talking (too close to each other), or maybe a dirty MAF.

2. Intake bolts loose and causing oil to drip down engine. Check the TQ of the intake bolts (might want to replace gaskets too)

3. Much tougher to judge. I'd guess its an intemitent misfire. Could be a dirty injector, a weak spark, or some forign material causing an incomplete burn (like oil or coolant) leaking into the combustion chamber.

Little smoke on startup of a SBC is an age old sign of leaking valve stem seals. Is there a SBC w/100k+ miles that doesn't give a puff? ;-)

I'd: Check all vacuum hoses, clean the MAF wire (special spray), reset the TPS, put a little dielectric grease on all engine related electrical connections, check battery ground wire, and check ignition system strength. (resistanc in plug wires, plugs gapped properly)

Rebel Rev

Booking it in for a tune up... had it over a year without a tune up and most likely the previous owner didn't get it tuned for some time as well.

Use 91 Octane

Rebel Rev

Yes, an Aussie... RHD...

touyech2883

Check the exhaust manifold for a cracke or the sec air injection for leaks.

Rebel Rev

The weird thing is the car idles perfectly and country drives are smooth and the engine runs well. I checked out the EGR tube and it seems fine and I think the smoke on cold start up comes from further down, mostly likely from the catalytic converter area. There is two of them on each side.

Yes, not too worried about the puff of smoke on start up as I was told when I first bought the car that was a common thing.

Will check the things you highlighted.

Thanks.

Rebel Rev

Checked it today and all looks fine. No leaks either end.

Rebel Rev

Got my partner to start the car when I was laying down on the right hand side with a torch and beamed it on the right hand side catalytic converter.

There it was on cold startup, a puff of smoke came out of it. Probably why I have that 'putt putt' sound coming out of the exhaust on the right hand side as well.

Cliff Harris

Sounds like loose exhaust manifold bolts. When mine came loose one of them was sticking out about 3/8". It always seems to be the two rear ones that loosen...

blackozvet

Howdy Rebel, just curious, what suburb are you from, are you a Corvette club member ?

Rebel Rev

No not a member. It's RHD.

I am more of a motorbike person and ride them a lot. I loved the look of the C4 and had to have one.

Rebel Rev

Next week it's going into get checked... will get whatever it is fixed.