Volvo 175a - Low oil pressure, Low comp. in #3 cyl

seanrh1

Recruit
Joined
Jul 26, 2005
Messages
5
I recently purchased a 20' '69 Fiberform Spokane model with a Volvo aq175a 6cyl engine. Boat was sold by a friend of the widow of the owner so I didn't get much info on the engine. I do know that it is not the original and has been in the boat for several years.<br /><br />Engine runs strong, starts fine when cold. Oil pressure after warm up is a third of the way into the green on a gauge that goes to 80psi but has no other number than 0. At idle the pressure drops into the red after running at cruising speed (3500-3800rpms). Possible problems?<br /><br />I checked the compression in all cyl and came up with all but one in the 150-130 range and cyl #3 at 50, this is definetely a concern but I'm hoping to make it through the rest of the summer before tearing into the engine. Rings or stuck valve for the low compression, what else?<br /><br />Any other info some of you may have about this engine would be great, I need to decide today about what repair manual to get Clymers or Seloc.
 

Don S

Honorary Moderator Emeritus
Joined
Aug 31, 2004
Messages
62,321
Re: Volvo 175a - Low oil pressure, Low comp. in #3 cyl

Engine runs strong, starts fine when cold. Oil pressure after warm up is a third of the way into the green on a gauge that goes to 80psi but has no other number than 0. At idle the pressure drops into the red after running at cruising speed (3500-3800rpms). Possible problems?<br /><br />I checked the compression in all cyl and came up with all but one in the 150-130 range and cyl #3 at 50, this is definetely a concern but I'm hoping to make it through the rest of the summer before tearing into the engine. Rings or stuck valve for the low compression, what else?<br />
With one cylinder down to 50, I doubt it runs strong. May sound ok to you, but it would probably sound like S%@# to me. But I can tell when an engine is down a cylinder just by listening.<br /><br />While it may now be a leaky valve or something minor, running it can turn it into an engine replacement. <br />With the low oil pressure when warm, you may have bad bearings. Has the engine ever had salt water in it. Oil or cylinders.?<br /><br />As far as manuals go.<br />1st choice would be the Volvo manual<br />2nd Seloc<br />3rd........... Not Clymer. A WAG would be better.<br /><br />PS: WAG = Wild A$$ Guess
 

seanrh1

Recruit
Joined
Jul 26, 2005
Messages
5
Re: Volvo 175a - Low oil pressure, Low comp. in #3 cyl

While it may now be a leaky valve or something minor, running it can turn it into an engine replacement. <br />With the low oil pressure when warm, you may have bad bearings. Has the engine ever had salt water in it. Oil or cylinders.?
I don't really know any history on the engine, just that it hasn't been run in a few years.<br /><br />Just because it is down to 50 does that mean it may not be doing anything at all?<br /><br />I pulled the valve cover and turned the engine over and it is nothing obvious like a bent pushrod or broken rocker stud. Everthing seems fine on that end.<br /><br />Volvo manual is on the way, I will prolly tempt fate and run it as it is for a while.
 
Top