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I totally forgot I dumped a can of seafoam into the fuel tank last week.That's why the spark plugs look black.
Oh I didn't bring the post up to speed on why I tore into it.

My 10 hour old engine oil with Marvel Mystery oil now has a hit of Gas in it.
I was reading that cars run rich in cold weather and some gas will get pass the rings and into the crankcase.
This car just does not like the cold weather. It's not getting up to full temperature to burn off those gas vapors in the engine oil.
When I'm at a stop, the temperature will go to the half mark where it supposed to be,but when in motion it drops 2 notches.
I'm just going to change the engine oil and put her to rest for the winter.
It sounds like you have thermostat that is stuck open...The car should get to midway point on the gauge and then just stay there...Jason
 

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Discussion Starter #42
It sounds like you have thermostat that is stuck open...The car should get to midway point on the gauge and then just stay there...Jason

Jason, your a scholar and a genius ..:)

I was reviewing my videos of the temp swing during the summer driving and the first day I bought the car.
The temp needle will sits on the half mark at the lights and drops when on the move. I am sure that thermostat is the root to all of this evil...... I'll be jumping on that this week.
By chance would you happen to have a part # for a replacement Thermostat ?
Thanks Jason
 

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Discussion Starter #43
Rennz................ Does the ZF-6HP26 Transmission / Gearbox has a torque converter OR Clutch plate?

Seeing that I do have the ZF Transmission, I don't have to remove the diff to get the transmission out ?

About the Injector leaking into the cylinder..........I will try what Jason said about the stuck thermostat first and see if that fixes the problem. ;)
 
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Thanks, but I have just been doing this a long time....I don't know the part#, but you'll need a o-ring as well...Leaking injectors will usually give you a misfire for a few seconds when the car is restarted as the car clears the excess fuel out of the cylinder...Transmission has a torque converter and only requires driveshaft removal....Jason
 

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Discussion Starter #45
Thanks, but I have just been doing this a long time....I don't know the part#, but you'll need a o-ring as well...Leaking injectors will usually give you a misfire for a few seconds when the car is restarted as the car clears the excess fuel out of the cylinder...Transmission has a torque converter and only requires driveshaft removal....Jason

Music to my ears....Thanks Jason


This engine does exactly what you described with regard to a leaking injector and misfire. I get that popping sound from the right side exhaust after about a minute from first start up.
I'll work on replacing the thermostat first. My next startup will be when bleeding the the coolant system. I'll run a leak down test on the injectors at that time.
 
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Injectors don't leak much these days...Every car I work on has Bosch injectors...I have replaced 0 in the last few years for leaking and only a few for anything else...Direct injectors are a different story...Jason
 

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Discussion Starter #48 (Edited)
I did the fuel pressure test today
When engine is started it holds @ 50 psi
Engine OFF Pressure drops from 44psi to 36 psi in one hour.
take a look.

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That looks about right..You have to remember that the fuel pressure regulator is going to leaking some in the fuel pump assembly...Cars that have leaking injectors tend to blow out a dense white smoke when you start them...Jason
 

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Discussion Starter #50 (Edited)
I'm leaving the pressure gauge on the fuel rail to see what happens ...
It's been 2 hours and it's still dropping.

Jason if it's the fuel pressure regulator I'll leave it alone, no harm.
The gas smell in the engine oil is my issue here. I just might pull the injectors and look for a culprit.




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It is going to drop and it can't hold 50 PSI forever...If you had an injector leaking and lets just assume it is just one, because I never replace them for leaking...Wouldn't you have a nasty misfire as all that fuel was trickling into that cylinder? Plus you would have smoke from the raw fuel not being burned..Having a thermostat that is stuck open is like driving a car with the choke on BTW.. This is probably not helping your issue....Didn't this start as a engine noise? Kinda all over don't ya think? We have gone from engine noise, not running up to temp, to now a leaking injector...Sure you are not just smelling the oil additive? I would start with the thermostat before I started removing fuel rail...Like I said....Replaced 0 injectors for leaking and every make on work on has Bosch injectors...Newer injectors are disc style and not pintle and are not prone to the issues earlier cars had, but it is possible..Jason
 

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Discussion Starter #52
I hear you.
Ordered the Thermostat and O ring from Scuderia it will be here on Thursday, I'll replace it then.
It was minus 1 today. Took the car for a 20 min drive on the HWY the engine temp stays 2 notches below 90 the whole way.
This Maserati is truly mine to discover :censored:
 

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I have replaced a leaky injector or two, (not on a Maserati). A still functioning injector with a small static leak will usually not be bad enough to foul the plug, but sometimes have a rough/rich start with a little black smoke. White/blue smoke on startup is oil related, usually leaking valve guides. When the fuel leaks into the cylinder, it seeps past the rings taking the oil on the wall with it, causing ring and cylinder wear. If it gets bad enough to dilute the oil, you can obviously have bigger issues.

I am leery to jump to the injector conclusion based on a description of the smell. The normal combustion byproducts mixed in the oil may smell a little like fuel to some....
You should have a sample sent for analysis; it can tell you a lot about your engine.
 

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Discussion Starter #54
5 Hours into the pressure test
I know what engine oil supposed to smell like.

I have 9.5 liters of old engine oil that came with the car when I bought it with only 8 months runtime.. No Gas smell.
I have 9.5 liters of new engine oil with 10 hours on it mixed with 1 liter of Marvel Mystery ..................... Gas Smell
I have 9.5 liters of new engine oil with 20 min run time on it ....................................................................Gas Smell
The Fuel Pressure Testing is dumping gas into the oil Or the engine is not getting up to it's 90* operating temperature due to a faulty thermostat causing a rich fuel condition and getting passed the rings...




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Well sounds like you got it narrowed down, though I'd also do a compression check (possible damaged ring..).
Good luck.
A damaged ring would have low compression and flag a misfire fault...I like to make things less complicated and more likely based on product knowledge..Just saying....Jason
 

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Not disputing the fact that he may have a thermostat issue, but the coolant temp is reaching at least 150 deg F based on the description. If the engine were running rich enough at this temp to send unburned fuel into the oil, it would be smoking like an old diesel and have misfire codes. Which leads me to believe the fuel is entering in a static or other condition.

As for minor ring damage, most conventional engines will have an increase in oil consumption or white smoke and misfire as it gets worse because oil is pulled into the cylinder during the intake stroke. Engines (like the F136, Ford coyote...) with a crank case vacuum pump can offset the intake stroke vacuum and the oil consumption is negated; instead some of the intake fuel air charge can be pulled past the rings before the compression stroke is completed. The cylinder will still fire with the now leaner mix in the lower compression without knocking or throwing a code.
The noise under load can be caused by the uneven compression (blow-by) on one side of the piston causing “piston slap”. On a tight tolerance engine, it wont be as loud or extreme as an older engine or diesel starting in sub zero, but more like a cold race engine with forged pistons.

Engines are engines; there’s no mystical differences between how a Ferrari, Toyota, race, or Briggs and Stratton sucks, bangs and blows.
 

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This is a forum. Internet diagnosis.
I think it's fair to give ALL possible scenarios as an educated guess.
There is no substitute for proper hands-on testing.
 

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Discussion Starter #60
Ok guys back on track,, As I have one day to kill before the thermostat arrives tomorrow I would like to do a compression test on the engine today.

Question
should the throttle plate be fully open Or I could just remove it ?
should I disconnect all injectors. or is there a fuse that should be pulled ?
should the engine be up to temperature before the performing the compression test OR Cold ?
Should I do a wet test as well ?
This engine has 78k on it, what's your guestamate the reading should be.
 
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