1986 Volvo 240, odometer stopped working at 130k miles so mileage unknown.
Had a slight knock when bought, but was so slight that I thought maybe it was something else.

Since then I've driven the car 400 miles to LA twice, once while towing a 2000lb Volkswagen. I've also Rally Crossed it twice...

Now I've recorded the sound but it's only really audible in the first half of the recording. I'm thinking it's a main bearing... and I guess the only way to really know is to drop the oil pan, which is the plan this weekend. I know with rod bearings you can check play via spark plug... but doesn't sound like that.

When the engine is under load it is worse.

Audio:
https://www.dropbox.com/s/vbrqdx7e42...B2%5D.3gp?dl=0


tldr; If you're asking what the hell I want, just tips! I have rebuilt a motorcycle motor before but that had roller bearings and was a bit different. Watched a lot of videos and such so let's see what I find this weekend!

 

i've never heard of the bottom end failing on one of these engines, unless it suffered from serious neglect, like being run with no oil pressure. we've got about 500000 miles on our 1987 240, 2 teenagers learned to drive in it and took it off to college, numerous nanny's and babysitters drove it before the kids were old enough, my wife is a leadfoot, she was the original owner, I drove it for awhile fixing it back up between the nannys and the teenagers, and *I'm* a leadfoot. its never even had a head gasket replaced, although we did have to do the valve cover gasket a few years ago as it was getting kinda oily.

frankly, I'd find another motor in a junkyard and just swap, if it really proves to be bottom end.

 

Yeah I know the redblocks are famous for reliability, that's why I'm startled about this.

 

To properly check the main bearing clearances you need to get some Plastic gauge. You can get it at most auto parts stores but the last time I went to Autozone they didn't know what I was talking about when I asked for it. Eventually they discovered that the actually stocked it.

To use it, you remove the bearing cap, cut a piece of plastic gauge off and place it on the bearing journal and put the cap back on and torque it to the proper setting. Then remove the cap and measure the width of the piece of plastic gauge. The plastic gauge package actually has a ruler that you use translate the width of the deformed material to a bearing clearance. I would do this for all of your main and rod bearings.

 

You can get a running b230 motor for a couple of hundred bucks pretty much anywhere--they are the last thing to go in a Volvo... Much better (cheaper) option than getting into rebuilding, unless you want to tinker.

 

Thanks.

 

Perhaps, but don't want to do a complete rebuild. Simply checking and replacing bearings is something I can do on my street. Replacing a motor is a bit harder to get away with.

 

No sludge in top end whatsoever, compression is 180/190 across the board, did not find any play using dial rod test.

I really didn't want to drop the oil pan, because of that cross member. Dammit.

 

Changed the oil, Mobil 1. Sound went away. It was very, very, very black.

 

if it was that black, I do believe I'd plan on changing the oil and filter again after driving a 100 miles to get rid of more of the sludge. I probably would have used the cheapest 10W30 I could find for that first change, then the good stuff for the 2nd change with a new mann oil filter.

 

Yeah the shop I went to on my block had Mobile 1 or some very questionable brand... I plan on changing it again soon including the filter.

 

nothing wrong with mobil 1. Its what I usually use in my volvo (10W30). I've been putting chevron delo 400LE in my mercedes as it likes 15W40 in my climate. it also uses 8 quarts.

 

Wow, 8 quarts!

I meant that my options were either Mobil 1 or something questionable, so I got the Mobil 1.

 

Couldn't make heads or tails of the sound bit you posted.

I'm sure Mobil 1 is great stuff, but I generally go for the cheaper conventional oils. That's what these engines were designed for, so I stick with that.

The molecules of conventional oils are bigger than synthetic oils, and in theory, that means that synthetic oils move easier through the system easier and come up to temperature quicker. These are good attributes.

But, there are always trade offs. Engines that didn't have oil leaking problems sometimes develop them when changing to synthetic, because of this. I know of at least one example I was involved with where we starting using synthetic oil, and it developed oil leaks. Switching back to conventional oil, it went away.

Newer motors--such as the motors in the XC70 or V70R--can stand to benefit quite a bit from synthetic oils, as they have more intricate & smaller oil duct systems to trigger things like variable valve timing. The have a tenancy to gum up. But using synthetics has shown good results of alleviating such problems. (This I know first hand.)

But, on an old red block, the oil doesn't do much, except lubricate, and not through particularly small orifices. But you say, "but doesn't the synthetic oil get to the relevant journal bearings better if it is a lighter oil? And isn't that good?" In theory, yes and yes. In practice, I'm skeptical. Far better is driving your car easy until it warms up. There is no doubt *that* will help prevent premature wear.

As to synthetic oils on red blocks, I think that it is a bit of a waste.

But, that's just my two cents.

 

Thanks for your opinion. I have no leaks so I'll stick to synthetic. It's only like $10 more every 5k miles.

 

Okay, noise came back and is worse. Checking oil filter today for debris and will try some oil stabilizer... it's the worst when the motor is cold, then it quiets pretty quickly. It's a dull thud. I really would like this motor to last a bit longer, but maybe time for a 230FT swap?

 

I've had typical piston slap on our 89 for the last 200,000 miles. No big deal just sounds like a diesel when idling. I would bet you have the same thing. Take out the low oil pressure sensor near the oil filter and stick a gauge in it. Check the oil pressure at idle and rev it to 3000 rpm and check it there. If it is all normal then I would bet it is piston slap. If that is the problem you can either rebuild it or let it go and just put up with the noise. By the way I use 10W-40 plane old dino oil.

 

I'll do that! Never done it before, what size of tubing does the gauge need to have, or is there like a common size?

 

1/8" will do.

 

um, an oil pressure gauge would need to be threaded into the hole, so it would to ahve the same thread size as the stock gauge or it would just blow out under the pressure (which is likely around 45 PSI or something).