Mercruiser 1.7 DTI Diesel

[spannerman]

Was looking at the inards of 2yr old blown 1.7 today, it had a crack through No3 piston, the cause was something as simple as the shaft which operates the waste gate on the turbo had seized up resulting in the turbo over boosting the engine and blowing a piston. Then found out that another dealer had had two more with the same problem. Anyone who has tried this engine knows it is a great performer for its displacement and had tremendous torque, but seeing as its a modified Isuzu unit I suspect that the turbo was designed to operate in a relatively dry engine bay in a car. Now it finds itself in a damp salt laden atmosphere so this problem has arisen on three engines in this area alone, I know several forum members have recently bought these so I would suggest a periodic check of the shaft where it goes into the waste gate housing and a little lubrication wouldn't go amiss, not sure what to suggest as this bit gets very hot and ordinary oil will probably make a lot of smoke. But a little maintainance here could save a costly engine rebuild.

 

[truebrit]

COPPASLIP is used to lubricate furnace doors, so will probably work on a turbo wastegate shaft

 

[mercman]

You must of missed the wastegate modification a year ago. All 1.7 had a change of wastegate and been changed under warranty even if the engine had no problem at all. Other problems were the dampers breaking but these to have been changed. Check your parts bulletins its all in there. Any one out there consult your merc dealer if this thread has scared the pants of you. It is also a diffeent turbo to the vehicle unit.

 

[Dave_Snelson]

Exellent advice Spannerman. I don't doubt the performance of the 1.7 and it is widely utilised. I think also, that there is a wider issue here in the new range of highly powered diesel motors from Volvo / Mercruiser. I don't think I'm wrong when I say that this subject has been done before on here and it relates to the reliability and longevity of these engines. This subject needs revisiting in 4-5 years from now.

Time will tell...

 

[spannerman]

I just tell like it is, we all know that not every customer gets to hear about Tech Bulletins. I agree with Dave, the latest trend is to squeeze more and more HP out of smaller blocks, which is great with car engines which don't operate under full load all the time, whereas a boat engine is working hard most of the time, I guess time will show how these car derived engines last in marine aplications. I know we have had problems with injectors already on Volvo D3's. The engines of yesteryear were not stressed compared to todays engines so thats why I guess so many are still going strong.