Oil Pressure issue......?

[fogducker III]

So the 18C has had quite a few hours added to her lately, during the last couple of times out I have noticed a lower than normal oil pressure as well as a "hard" starting issue.........hard to describe the starting but it almost seems like the starter is labouring trying to turn the motor over...? When I turn the key there is a slight delay and then it will crank the motor but it seems like it almost doesn't have the snot to turn the motor over, it always starts but lately with just more effort...?

My oil pressure use to read 20psi at idle, 40psi at cruise and almost 60psi WOT. Now I get just under 10psi at idle, about 20psi at cruise and about 40psi WOT...?

The starter is less than two months old and I have always run 20W - 50 Royal Purple oil. When I got back from our trip I ran a good engine flush, changed the oil and filter and still no change, perhaps the oil pump is on the way out? But that doesn't explain the hard start.........any ideas...???

PS. Other than the start and lack of pressure the engine appears to run well.....

[olredalert]

-------If you still have some of the oil have it analyzed by one of those oil check services. I dont know, but it sounds like you may be punishing a bearing or two a bit too much. Thats a problem you want to catch early if at all possible. Costs a bunch less to fix early as opposed to LATE!!!..........Bill S

[fogducker III]

-------If you still have some of the oil have it analyzed by one of those oil check services. I dont know, but it sounds like you may be punishing a bearing or two a bit too much. Thats a problem you want to catch early if at all possible. Costs a bunch less to fix early as opposed to LATE!!!..........Bill S


Thanks Bill, I am not sure exactly what you mean? A crank bearing...? or...? How would that effect oil presure and would the starting issue be a sign of that...? I still have the old oil filter full of oil in a bucket in the garage, I will see if there is anybody in this "small" town that can check it out........:(

I really hope the motor is not on the way out, if it can last through the summer, perhaps this winter I should slip one of those "purdy" motors Mr. Harbourmaster is building....:eek:

[olredalert]

-----It would more likely be a crank bearing wearing prematurely but could be a rod bearing as well. Once they lose enough theres too much clearance there and the oil pressure goes down. If one of those bearings is doubling up on itself it could create the starting problem you have outlined. Too much drag on the crank. The good thing about finding a problem at this stage is that you may not have to do a complete rebuild. If the engine was in a car Id just tell you to yank the pan off and take a looky, but being in a DONZI sort of necessitates a yank. Unless somebody else has a better explanation I wouldnt use the boat again until I knew what was going on in there...........Bill S

[BigGrizzly]

Here is what I would do. Get a manual oil pressure gauge and re check. I once had the same issue and it was the oil filter. The hard start thing related to crank bearing if it was causing the hard start it would show up in a hurry unless Royal is really something special, and I doubt that.

[fogducker III]

Thanks boys, I agree Grizz, oil is oil and the "apparent" loss of pressure points to a possible internal problem.........silly question, but where do I take the reading from with a manual oil pressure gauge?

Second question, if this motor is heading south, I think grabbing a good rebuild 350 block and building that now and just swap over the external parts might be a good idea? I really am not sure what the exact specs are on the 377 Scorpion...? I know the heads are vortec and most of the guts are stainless (valves, seats, push rods etc) and I beleive the whole motor is rollerized???

Not really sure where to go with this, there is not really anybody local that could handle a rebuild of one of these Scorpions, mainly because of the low numbers of them...........suggestions for an engine replacement?

I am looking at the GM LSA motors as well as the motor Habourmaster is putting together...?

Or should I just pull this motor, break it down, repair what is needed, as pointed out, likely bearings and/or oil pump, and hope for the best?

[BUIZILLA]

your getting wayyyyyyyyyyy ahead of yourself...

[fogducker III]

your getting wayyyyyyyyyyy ahead of yourself...


Your right Buiz, I know, I just don't want to be without a boat for the summer, might be a minor problem, but low oil pressure (gauge was working fine before and I have no reason to doubt it now) and the hard start issue does not look good. What else could it be? Either way it looks like I need to pull the motor, right?

Or do I just run it until it blows up and then figure out what motor to put in...:eek::lookaroun::boggled::toiletpap

[fogducker III]

Ok, Ok, I thought I could convince Jacqui that I needed a new one of these......

http://www.gm.com/experience/technology/gmpowertrain/engines/specialized/marine/2009_6200_LSA_Marine.pdf?exist=false

But she read your posts and suggests I fix what I have........:boggled::bonk:

I will pick up a manual oil pressure gauge and have a look at the real pressure, check the ground wires etc for the starter and pull the oil cooler and have it flushed and tested, anything else I should look at while I am there???

The motor was running perfect and then he TWO problems started at the same time, that is what worried me.

PS. I think I will do another compression test........thanks again.

[MOP]

As far as the slow starting check connections especially the grounds, they have to be clean and tight.

If the oil gauge you buy is 1/8" pipe thread look at the front of the engine top forward there is a 1/8" plug in the blocks oil gallery. You can screw one in there and leave it for checking any time you open the hatch, also you can compare to your dash gauge!

Phil

[osur866]

Junk the scorp. and put the ls based engine in get it dialed in then call me so I know what to do when I get ready to go that route. hehe :tongue:, serouisly there's prolly nothing really wrong with what ya got stay the course and check things out. Steve

[BUIZILLA]

are the rest of the gauges reading accurate?

[DonziJon]

Pull the OP sender, screw the gauge in there. As far as 10PSI hot, I've seen tons of SBC's do that for years on end. Usually a heat issue, if it is a new trend maybe the oil is getting hotter than before due to a cooler problem? No laptop here today, can't look to see if it has one, but I thought it did.
Starter can be just a defective starter, or a bad ground.
Quit looking for an excuse to repower ;) :) :D :p
Wait, what am I saying? it's toast, buy a new one, ship the junk one to me for a proper burial :D :D :D

I'd go for a BLUE Motor....What the hell. You're only young once. ......Right? :nilly: John

[fogducker III]

are the rest of the gauges reading accurate?

All gauges are 100%...

As I said, the weird thing was that both problems started at the same time, the motor runs like a champ and there "appears" to be no other issues then the low oil pressure and the 'slow" start.

I will do all the checks suggested and see what comes up, thanks for all the input as usual.........:yes:

[mrfixxall]

Dont put anything in your engine but oil ! when you flush a engine with chemicals it washes all the crap into the oil pan a d plugs the pick screen on the oil pump and will cause your engine to starve for oil..
do what everybody tells you ,install a manual guage and get it hot to get accurate readings.

My sbc use to go down to 10 psi after a hard run,since then i put a qt of lucas oil treatment in at every oil change and now it dont drop below 20 psi at idle..try it it works great,been using lusas in my suburban since day 1 and it just turned 444000 on the odometer..oe everything including the timing chain(knock on wood)

[yeller]

I'd pull the spark plugs and belts off and see if you can turn the motor over by hand. Grab the crank pull and try and turn it. If the starter is noticeably laboring to turn the motor over and it is being caused by an increase in internal friction (for whatever reason), you will NOT be able to turn it by hand. If you can spin it by hand, I'd say the insides are good.

[Lenny]

Or do I just run it until it blows up and then figure out what motor to put in...:eek::lookaroun::boggled::toiletpap

If you do, I have a couple spare boats you can go out in this summer and try to blow up. But, the motors are near new so it might be a challenge :D

[fogducker III]

If you do, I have a couple spare boats you can go out in this summer and try to blow up. But, the motors are near new so it might be a challenge :D


Thanks for the offer Lenny, I just hope the problems with my boat are not terminal.......:(

PS. If I did "borrow" one of your boats it will take me a couple of days to clear the dust off eh? :eek::lookaroun::canada:

[Lenny]

Thanks for the offer Lenny, I just hope the problems with my boat are not terminal.......:(

PS. If I did "borrow" one of your boats it will take me a couple of days to clear the dust off eh? :eek::lookaroun::canada:

Sad, but true Jeremy. The last 4-5 beautiful days (perfectly clear and sunny) I have been putting in a kitchen/bath/laundry for a home that gets oppupancy June1st. :eek: I am about 75% done. I did run the X on the hose on Saturday and some 3-4k blasts just to let the neighbours know that they are still here, tucked away, but ready t roll :D (just dusty)

You know that they have been sitting too long when you can feel the flat spot on the tires when pulling it out. :(

[VetteLT193]

check the wiring. thoroughly

[Lenny]

What about timing ? Could that be an issue? Being electronic I highly doubt it and that says nothing towards the oil pressure issue.

[fogducker III]

What about timing ? Could that be an issue? Being electronic I highly doubt it and that says nothing towards the oil pressure issue.

Timing passed through my mind as well but the engine itself runs perfect at all rpm's, perfect idle, cruise and wot, picked up the oil pressure gauge today and will try and have a look at things tonight...........:wrench:

[VetteLT193]

I'd put money on a short. From experience. Check the wiring before spending a dime. If you don't have a good electrical tester, now's a good time to buy one of those first.

[fogducker III]

I'd put money on a short. From experience. Check the wiring before spending a dime. If you don't have a good electrical tester, now's a good time to buy one of those first.

A short on what, the starter? It is brand new and has not given me a problem until the low oil pressure issue started, the starter engages and starts the engine it is just that it is slow and laboured.......I have checked the two wires to the starter and they are fine........I will install a manual oil pressure gauge tonight and see what I have...........

[VetteLT193]

A short on what, the starter? It is brand new and has not given me a problem until the low oil pressure issue started, the starter engages and starts the engine it is just that it is slow and laboured.......I have checked the two wires to the starter and they are fine........I will install a manual oil pressure gauge tonight and see what I have...........

could be anything that is powered when the key is turned to the on position.

This has every sign of a short IMO. It could be the starter itself is bad and shorting internally. It's easier on a carbed engine because you can unhook everything and start at the base engine. EFI is tougher to see if it is a short because there is only so much you can disconnect.

FWIW I just had this EXACT problem.

[mrfixxall]

(starts the engine it is just that it is slow and laboured)

Are you sure your not getting water in a cylinder to cause the starter to labor?

[fogducker III]

(starts the engine it is just that it is slow and laboured)

Are you sure your not getting water in a cylinder to cause the starter to labor?

Good point, I am planning on pulling the plugs as well tonight, doing a compression test and going to try and turn the engine over by hand as Yeller suggested to check for any internal "binding".....

[fogducker III]

OK, I LOVE YOU GUYS! This is why I post on this site and don't take my boat to the nearest "marine mechanic"............!!!

I owe you ALL a beer or two!

I got a manual oil pressure gauge, removed the electric one and noticed a chunk of crap on the end of it partially blocking the intake hole, cleaned it out and thought that was the pressure problem but just to be sure I installed the manual one. Hot at idle, 20psi, just over 2000rpm, 30psi and reving it to almost 4000rpm, 40psi, on the hose hard to get WOT but you get my point!!!:)

I replaced the electric sending unit after cleaning out the crap from the hole, same numbers!!!:yes:

Did a compression check, 140psi EXACTLY on ALL 8 holes.........:eek:

Now the starting issue was another thing, checked all the wiring numerous times, nothing, then I remembered when I installed the new smaller high output starter I dropped a washer into the bilge removing the old one, made a mental note to retrive it when installing, obviously didn't, the slight angle must have been enough to let the bendex "bind" up when engaging...........:boggled:

I retreived the washer, removed the starter, installed with all the parts in place and vroomm!!! All is good!!!!!!!!!:hyper:

Again, I thank you all for the input and ideas on areas to look, I am now taking Jacqui out for dinner.....:popcorn:

[Lenny]

You make me laugh. :D Today at work a co-worker says to me, were you out yesterday? (or on the weekend, I can't remember) anyways, I said no, I was installing millwork in town and he said that it was cooking and that the guy was really on it. I said, that would be Jeremy. Same boat to look at at a distance.

Anyways, here we are again, you are running the $iss out of the Scorpion, it loves it as do we, and when catastrophe struck it was a $30 fix. :)

I like your luck with this stuff :yes:

See you soon, finish this job, finish the University, one more modest kitchen and I am in the water. :)

Maybe on Saturday if I take a break next weekend.

Take care, Lenny and Deneen

[fogducker III]

You make me laugh. :D Today at work a co-worker says to me, were you out yesterday? (or on the weekend, I can't remember) anyways, I said no, I was installing millwork in town and he said that it was cooking and that the guy was really on it. I said, that would be Jeremy. Same boat to look at at a distance.

Anyways, here we are again, you are running the $iss out of the Scorpion, it loves it as do we, and when catastrophe struck it was a $30 fix. :)

I like your luck with this stuff :yes:

See you soon, finish this job, finish the University, one more modest kitchen and I am in the water. :)

Maybe on Saturday if I take a break next weekend.

Take care, Lenny and Deneen

Len, you da man..........:cool:

As you obviously do, I love running this boat and any others I have had hard, at times maintenance is a must and sometimes I get lost, but I try and gather info and get her done myself, hate paying others to do most of what I can do, having said that, if I can not fix it or do not have the tools, I pay the people who can but around here, very few can, so I am learning ALOT..........:yes:

I enjoyed running with you Lenny and realize you have $hit to do, you will get out when you get out, I will be at your 3 o'clock.............:canada:

[BigGrizzly]

Fog, That piece of crap may have come from the flush. Now my suggestion. Since you have just changed your oil I would do it again unless you have expensive oil if so change at least the filter again because of the flush. Now don't do that again your engine is too young. I am on Fix's side on this, he must be as old as me.

[fogducker III]

Fog, That piece of crap may have come from the flush. Now my suggestion. Since you have just changed your oil I would do it again unless you have expensive oil if so change at least the filter again because of the flush. Now don't do that again your engine is too young. I am on Fix's side on this, he must be as old as me.

I realize now the "flush" was not a good idea........:(

I will run the boat for a couple of hours and change the oil and filter again, other than that, I am a happy camper............:)