Oil fiter blew off at full throttle Mercruiser 4.3LX

[mr-steve-jones]

Hello Guys,

Today's fun was scuppered when the Solas oil filter on my Mercruiser 4.3LX V6 blew off. The bilge was full of oil and the filter was lying in the bilge.

The filter has been fitted for months, and has been ran many times, hard, without a leak. I started the boat at home this morning before going out and checked for leaks and all was fine.

I launched the boat.. ran slowly on tick over fine for 5 mins to get to a safe place on the river, oil pressure 40PSI as usual, water temp rising OK, then put full throttle. The boat ran for 20 seconds or so, then cut itself out. A restart attempt had the warning buzzer and zero oil pressure.

I lifted the engine cover and found the bilge full of oil :-(

There was no tow available as we were on our own, so to get us back to the launch ramp, I re fitted the filter tightly, and scooped the oil back into the engine using makeshift scoops and funnel from plastic soda bottles.

A restart, and the oil pressure needle flickered up, then back to zero.. Instantly I stopped engine, and the bilge was again full of oil, and the filter off again.

Eventually got a tow back.. Very grateful!

Has anyone seen this before? I have a genuine Mercruiser filter but don't want to fit it yet incase there is a deeper problem.

Any suggestions appreciated

Thanks.. Steve.

 

[Fishermark]

Re: Oil fiter blew off when powering

Re: Oil fiter blew off when powering

I've heard of seals blowing out due to having the old seal still on when you replace a filter.... but have never heard of the whole filter blowing off. Given everything you have mentioned I suggest...
... a faulty filter.
... the wrong filter
... the filter was crossed threaded
... the adapter plate threads are bad
--- a stuck pressure relief valve on the pump.

Easiest thing would be to buy a new filter and see what happens. Keep some extra oil and filter on board just in case!

 

[achris]

Re: Oil fiter blew off when powering

Re: Oil fiter blew off when powering

The V6 engines use a filter with a slightly smaller thread than the V8s. If you have inadvertently put a V8 filter on, that would account for the problem. Check the number on the filter and verify it is the correct filter for the model and year of your engine. The correct SOLAS filter is 1750103, but I would recommend a genuine for this application. It might cost a bit more, but how much did you save today?

Chris........

 

[Pete104]

Re: Oil fiter blew off when powering

Re: Oil fiter blew off when powering

+1 achris

 

[achris]

Re: Oil fiter blew off when powering

Re: Oil fiter blew off when powering

I just checked and the specs for the V8 and V6 filter threads are as follows:

V8: 13/16"-16 tpi
V6: 18mm x 1.5mm (pitch)

What this all means?

13/16" is 20.6mm and 1.5mm pitch is 16.9 tpi. So a V8 filter will spin onto a V6 stub, but it will only be hanging onto the threads by less than 1/2mm, so it is likely to stay there for a little while, then blow off.

Chris.......

 

[mr-steve-jones]

Re: Oil fiter blew off when powering

Re: Oil fiter blew off when powering

Thanks Chris..

I will check the part numbers out and also get the vernier out this morning on the Solas and the new Mercruiser ones I now have.

I will report back later today..

Thanks Chris and Fishermark for the advice.. Much appreciated

Steve.

 

[mr-steve-jones]

Re: Oil fiter blew off when powering

Re: Oil fiter blew off when powering

Just checked the part number.. Solas part 1750103 so that seems to be the correct part. (Acording to what's printed on)

Measured the internal diameter of the thread on the blown off filter with vernier - 17.5mm (thread peak to peak internal dia)
Measured the internal diameter of the thread on the new Mercruiser filter (35-883702Q) - 16.7mm (thread peak to peak internal dia)

Thats a 0.8mm difference in diameter.

I then measured the threaded spigot the filter screws onto. 17.75mm ouside thread peak to peak dia.

That means the Solas was hanging on by just 0.25mm of thread. How I've ran this since June is a miracle. My Dad suggests that with not running it for a month the filter medium became a little more clogged than when new, and the extra resistance in the filter gave that final push?

Plan today is to fit the genuine Mercruiser filter, new oil, and keep an eye on the pressure guage for the relief valve working OK.

Thanks for the guidance guys..

Steve.

 

[cliffblue]

Re: Oil fiter blew off at full throttle Mercruiser 4.3LX

I saw this 30 years ago on a ford truck. The pressure by-pass valve on the oil pump stuck closed and would pop the oil filter immediately on start up. I changed the oil pump and everything was ok. Good Luck!

 

[MarkySparky]

Re: Oil fiter blew off at full throttle Mercruiser 4.3LX

If the oil filter was mismarked and actually has the v8 threads I'd be talking to Solas about them picking up the repair cost.

 

[mr-steve-jones]

Re: Oil fiter blew off at full throttle Mercruiser 4.3LX

Changed the filter for a new one with a correct M18 thread. New oil.
Started up fine, tickover 40psi oil pressure, goes to 55ish at 2000 rpm and when revved the pressure stays less than 60.. No issue with relief valve. Ran for 10 mins fine.

Doing the maths on the Solas filter diameter is conclusive in my mind thats all that was wrong.

I now need to dump that oil and put a fresh filter on to know its all fresh & clean in there. Yet more cost :-(

Measured another M18 thread and its closer to 16.5mm and fits the engine nice and tightly.

Looks like I need to discuss this with Solas now.. Mr Jones is not happy!!! Worryingly, if it is proven to be a defect part, how many more people have them fitted???