Maserati Sebring unknown engine noise!

Dear all

I have a 1963 Maserati Sebring (series 1)

Ever since I got the car about 6 years ago their has been a strange noise from the engine. The noise has remained the same over the years. We just measured the valve clearances and except from the cylinder #4 exhaust valve they were all aprox. according to specs. The cylinder #4 exhaust valve is however 0,50 mm compared to the specs of 0,30 mm. Can this be source of the "ticking" noise that can be heard in the youtube url below:

https://www.youtube.com/watch?v=qAvIMgLpMBg&feature=youtube_gdata_player

Oils pressure is fine. We also measured the compression and all 6 cylinders was fine and within specs.

I hope somebody can give us their view on this matter. Is it only valve problem or maybe something more serious?

Best regards from Denmark

Anders

 

I think you need a stethoscope and a good ear
You should be able to hear if the sound comes from the top, or from crankcase.
If from the crankcase, very expensive, if from the heads just a bit expensive!
One valve 0.2 out can cause quite a bit of tick for sure.

 

Exhaust leak at header.
FGM

 

No its not a leaking gasket, might sound like in the video, but not IRL.
(I'm the one working on it

 

Your valve with 0,2mm too much clearance is a good candidate.

Best,

Jack.

 

Ciao,
i had the same Problem with a 3,7l Sebring!You have to loosen the timingchain,and then you are able to adjust the gap between crankshaftsprocket and the lower timingchainsprocket.
On front of the engine you can find the adjusting-lever(a aprox 5" long Lever).
Please don´t kill me if i´m wrong,but the noise is exactly the same.
Best regards,
bernhard

 

Bernhard,
If you are suggesting its a loose timing chain, we already tightened this before we did the video. Or are you talking about something else related to the timing chain?
When you stand next to the engine, it very much sounds like it originates from the top of the engine, not like a rod or gudgeon pin.
Best regards
Uno

 

Ciao,
the timingchain is not the Problem!
Short explaination:
On Front of the crank is a sprocket-that sprocket drives
Another sprocket,and that sprocket drives the Timing chain.
Means the timingchain is Not directly on the crank.
So you have to adjust the gap between that two sprockets,
And you have to loose the timingchain First,
Because if the chain is very tight,you aren't able to adjust the sprocket.
Cordiali Saluti,
Bernhard

 

Hi Bernard,
I now understand what you are saying, however I do not see any adjustment possibilities between the crank and the intermediate gear driving the chains. Are you talking about some type of sideways adjustment, rather than a eccentric movement, like is used for the chain tightening mechanism. I'm attaching a snip of the front of the engine. We are using the no. 20-25 for the cam chain tightening mechanism. So I guess you think about that something with the 28-33 could be used for some intermediate gear adjustment?
Best regards
Uno
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Ciao,
your Picture shows the 3500gt-engine.
On the sebring engine the intermidiate gear is excentric type.
You can see the adjusting Lever on my Picture.
cordiali saluti,
Bernhard
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Thanks Bernard,
I did not realize the difference between the 3500GT and the Sebring engine.
Thought the were basically the same. I will check for the adjusment lever on the Sebring S1 I'm working on.
Do you know if all Sebrings had this, or could it be something only found on the 3.7 liter version?

 

I´m not sure,i´m working on 3 Sebrings now,and they all have the adjusting Lever.
But the engines are 3,7 and 4,0litre.
Maybe your engine is the "old style" type.
Saluti,
Bernhard

 

This car is a series 1, with triplex cam chains.
I found a Mistral manual were it was noted that the doublex chain version had the the extra lever shown in your photos.

However as far as I can see, the photo you posted also seem to have a triplex and not a duplex chain.

 

Does not sound too bad for a diesel engine...
but certainly not what a 3500 should sound like!

Fully agree: buy a car stethoscope with the a pin adaptor (Google pictures shows them) and find where the noise comes from. I have used these stethoscopes for years now and one can even tell which exact valve has too much clearance! Perfect tool!

To me it sounds like coming from the engine top end, like too much valve clearance. I did put my Vignale Spider 3500 always on the thight side; outlet no more than 0.15mm and inlet 0.10mm!

Success with the search!

Ciao,

Bart

 

Would the exhaust clearance at just 0.15 mm be a candidate for having a burned exhaust valve after only a short time?
(used a screwdriver as a stand in for my stethoscope, and it sounded like coming from someplace in the cylinderhead)

 

Not normally, but in order to make sure the valve is ok you best do a leakdown test. If the same sound persisted for years, that's probably not the cause

There are many reasons for a noisy valve: Gap to wide, follower defective, burnt valve, worn cam-lobe, and a shim that's too thin causing the bucket to ride on the shim-holder instead of the valve-stem. .

Best,

Jack.