3.0L blown head gasket.... how common?

[Teutonics]

I was searching around and found a Mercruiser service bulletin for blown head gaskets on the 3.0L. <br /><br />How common was this problem?

 

[tommays]

Re: 3.0L blown head gasket.... how common?

11 years i am fine 1995 till now which service bulletin<br /><br />tommays

 

[Teutonics]

Re: 3.0L blown head gasket.... how common?

Mercruiser Service Bulletin <br /><br />It is only for 1997 and 1998 engines (mine is 1998), and my S/N is within the range of those affected (of course).

 

[Don S]

Re: 3.0L blown head gasket.... how common?

How long have you owned the boat? If you bought it new and haven't had any problem so far, and you don't hear any pinging, you shouldn't have any problem. If you didn't buy it new and it was previously owned, what is your SN, I can check and see if the head gasket was ever replaced under warranty.

 

[Teutonics]

Re: 3.0L blown head gasket.... how common?

Used, S/N OL083288. I'm assuming it has never been replaced. <br /><br />My concern is that the boat was running rough at idle the last time I had it out (ran great WOT but difficult acceleration), but it could be bad gas or other(?). I didn't hear any pinging, but... I wasn't listening for it. I haven't had a chance to do any troubleshooting, but now of course I'm fearing the worst. <br /><br />I'm going to try to do a compression check this weekend (along w/ fresh gas and carb cleaner) if I can find time and the weather cooperates. Are there any tell-tale symptoms that will let me know for sure one way or the other? <br /><br />If it is my mind playing tricks on me and the head gasket is fine, should I back the timing down (0 deg BTDC or the recommended 1 deg ATDC) and tighten the head studs to 95 lb.-ft. as a precaution to help prevent this from happening in the future?

 

[Don S]

Re: 3.0L blown head gasket.... how common?

You have a number of things that could be the problem other than a bad head gasket. Could just need a tuneup.<br />But I would start by pulling the plugs and checking for indications of water (rust on the plugs) being a 98, the riser or manifold or gasket between them could be bad. If that looks good, start the engine, warm it up and do a compression test..... a proper compression test. Here is the link to "How to" the compression test.<br /><br /> http://www.boatfix.com/merc/Bullet/97/97_25.pdf <br /><br />If that is ok, it could be just in need of a tuneup. When was the last time you changed the plugs, cap, rotor, checked timing, advance timing, adjusted carb etc.????<br /><br />I did check your records, seems your boat was never registered for warranty. Sounds like a "Low Rent dealer" never sent in the Mercruiser warrenty paper work for the original owner.

 

[Teutonics]

Re: 3.0L blown head gasket.... how common?

Originally posted by Don S:<br /> When was the last time you changed the plugs, cap, rotor, checked timing, advance timing, adjusted carb etc.????

I haven't done any of that yet, it's on the "to do list" for this weekend (or earliest convenience, but definitely before next outing)... assuming the compression check is okay!

 

[Teutonics]

Re: 3.0L blown head gasket.... how common?

Update....<br /><br />I did a compression check on the engine over the weekend, and it was 175psi on all four cylinders (+/- 2psi), so I think that rules out a blown head gasket! (whew!) So the next step I took was pulled the carb and there was water and trash in the float bowl... cleaned that out and am now trying to drain all of the gas/water before refill and starting it up. Keeping my fingers crossed!<br /><br />The engine appears to have electronic ignition (EST ignition = cap/rotor but no points), so will change cap and rotor next. Plugs looked new.<br /><br />So my follow up question is this: Since there is a risk of a blown head gasket on this engine, should I go ahead and back the timing down as a preventative precaution? (e.g. 0deg BTDC?)

 

[Don S]

Re: 3.0L blown head gasket.... how common?

If you noticed, the service bulletin did not mention changing the timing as a preventive measure. Only IF the head gasket had blown previously.<br />I would say adjust the timing normally as if it was not blown. Had the original owner had problems, he would have found it wasn't registered and Merc would probably have had them register it and the problem fixed (That is IF he had a problem) since it wasn't registered, assume it has been working fine and adjust the timing to the original spec.