JTS inlet manifold removal

Started by SeleMatt, July 22, 2024, 08:32:37 PM

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SeleMatt

Evening all,

The JTS has suddenly started drinking and thus, smoking oil. Pulled the plugs and number one is wet and carbony....the others look great. I reckon it's a failed inlet manifold gasket given the aforementioned.
If anyone has any time saving tips, I'd appreciate the heads up.
Looks pretty tight in there...  :-\ 

SeleMatt

So before tackling this job, I should do a compression check on cylinder 1 I guess.

Should warm it up before doing so? Probably not much point doing a wet test as it already is... ;D 

SeleMatt

#2
So I've just completed a dry compression test. Ran the car for 10 minutes and then pulled the plugs. They were all at 150 or a tad under. I found some other 156 JTS thread where the guy got 150 at dry and 220 wet. I think that establishes that my sudden oil consumption and blue smoke is due an inlet manifold failure as per this thread below where Baz states;

Ok, by telling me that #1 spark plug is oily you have just confirmed that is most likely oil leaking through the inlet manifold galleries. And for you and John, here is a photo of what happens when it leaks.
Also this is the easiest to check, just take the inlet manifold off. Below is a pic of culprit.

http://www.alfaowner.com/Forum/attachment.php?attachmentid=61215&stc=1&thumb=1&d=1480605040

Thoughts anyone?




bazzbazz

So I assuming that the #1 plug was oily and the rest were fine?
On The Spot Alfa
Mobile Alfa Romeo Diagnostic/Repair/Maintenance/Service
Brisbane/Gold Coast
0405721613
onthespotalfa@iinet.net.au

SeleMatt


bazzbazz

On The Spot Alfa
Mobile Alfa Romeo Diagnostic/Repair/Maintenance/Service
Brisbane/Gold Coast
0405721613
onthespotalfa@iinet.net.au

SeleMatt

Okay.

Think I may have given a bum steer earlier. Working from left to right, the cylinder in question is No 4; so next to the thermostat. Just took the car out and got it a lot hotter and did another compression test. Same result. All 150.

So given there's equal compression, is there anyway for oil to get into the bore of cylinder 4 like there is for the (gasket failure) of cylinder 1

bazzbazz

Badly worn Valve Stem Seals could be a possibility.
On The Spot Alfa
Mobile Alfa Romeo Diagnostic/Repair/Maintenance/Service
Brisbane/Gold Coast
0405721613
onthespotalfa@iinet.net.au

SeleMatt

So the engine only has around 60,000 on it and been fastidiously maintained with Penrite 10/60 etc. It was running perfectly and then literally overnight, it wasn't. Running downhill with your foot out of it and then accelerating again when that time comes, it blows blue smoke with the oil disappearing alarmingly quickly. It also stinks.
So beyond a cracked head or something, there's no way for oil to get into cylinder 4 via anything to do with variator down that end: no oil galleries through the inlet manifold down that end of the head?

bazzbazz

Quote from: SeleMatt on August 09, 2024, 06:45:19 PMSo beyond a cracked head or something, there's no way for oil to get into cylinder 4 via anything to do with variator down that end: no oil galleries through the inlet manifold down that end of the head?

Nope, as previously mentioned, with the symptoms you are describing the usual suspects are worn rings or Valve Stem Seals.

I have also seen instances of something (possibly a chunk or built up carbon) getting into one of the cylinders and badly scoring the bore, allowing oil to run past the rings into the combustion chamber. This resulted in the car doing an impersonation of a Destroyer on D-Day throwing out a smoke screen.

Unfortunately without being there to diagnose the issue there is little more advice i could give without just taking pot shots in the dark.
On The Spot Alfa
Mobile Alfa Romeo Diagnostic/Repair/Maintenance/Service
Brisbane/Gold Coast
0405721613
onthespotalfa@iinet.net.au

SeleMatt

#10
Okay thanks Baz.
The motor is evidently f....d.

Clearly the factory upgraded rings from balsa wood to pine didn't really achieve much.