Rebuild or just rering the pistons? (1 Viewer)

[ClemsonCruiser]

Okay, I have a 77 fj40 with a the original 2f engine. The engine has 52,000 miles on it , but the engine sat for quite a while before I purchased the cruiser last may. The engine has started to burn quite a bit of oil. It still runs good and gets me where I need to go, but I am tired of the burning oil smell and I know it won't last for ever like this. I had the compression tested on the cruiser when I bought it and the numbers all checked out to be within 10% of each other, but the numbers ranged from 105-115. I know this is rather low and in the rebuild range, right? So my question is can I get by with having the pistons rerung or do I need to have a total rebuild of the engine. I have heard that the engine can be rerung with it still in the cruiser, so I assume this is the cheaper route to, but is it the best? Please give me your thoughts on what to do and any idea of prices I would be looking at for a rebuild or reringing of the pistons.

Thanks in advance
JP

 

[Poser]

Not being able to see the condition of everything, will lead to generalized suggestions..

BEST- Take it out of the truck and go through it completly. You will spend 2K at least, unless you do everything your self, and even if you do the work yourself, you are going to be into it at least a grand for new pistions, rings, bearings, cam bearings, camshaft and followers, and Toyota gaskets/seals.


Depending on the condition of the cylinders, you might be able to get by going through the head, and installing new rings and rod bearings. Before deciding on anything, I would tear it down and look at things, and verify the reason for oil consumtion.

Good luck!

-Steve

 

[jim45r]

I agree with Poser re rebuilding in the truck. It could be done, but it's a lot of work, and you can't control cleanliness like you can when you've got the engine on a stand in the garage. If you don't get the cylinders REALLY clean after honing, your new rings wil get eaten up by the abrasive residue (at least that's what I've heard). Some ring manufacturers even discourage honing, but I'm skeptical 'bout that . . .
Did you squirt a little oil in the spark plug holes to see if the rings are the reason for the low compression? 52K on a land cruiser is just breaking in, unless the PO ran it without an air cleaner. Bad valve seals can cause oil consumption, too. Dormant engines can get sticky rings just from sitting, esp. if the engine was used for short hop driving in it's 52K of earlier life and had a lot of carbon build up.
James

 

[Jukelemon]

113 is the compression limit for a 2f. Your almost 10% below that on some of your cylinders. Try the oil approach to focus the issue. Don't think you need to go through everything. Just find the issue and take it from there. And like the above stated, you really will not know until you get into it. But suffice to say that if your compression is that low, there are definitely issues that would warrant at least a top tear down.

 

[IDave]

I agree with wet testing, if you haven't done it. It would be a shame to tear apart such a young engine (unless of course it really is 262000 or 162000 miles you have on it), if it is actually a valve or head gasket (less likely) issue.

 

[Ullr]

So how exactly does the "oil test" work? Put oil in the cylinders through a spark plug hole then see if compression goes up?

If it doesn't your rings are bad/worn?

 

[IDave]

A couple of teaspoons of oil will plug up (temporarily) leaking rings and improve the compression. If the compression problems are unchanged, it is head gasket or valve leak.

 

[ClemsonCruiser]

Thanks for the input guys, I will try putting oil in the cylinders and then test the compression to see if there are any changes and go from there.

Thanks
JP

 

[theo]

Something else to think about. My small block sat for almost 2 years before I got it running. At first it smoked so bad I thought about a rebuild. But I knew it was strong when it came out of the last truck, so I gave it time to "come around". And I used SeaFoam in it a couple of times.

Before you tear into it, you may want to run it for awhile, maybe with additives, to allow some of the goodge and sludge and varnish to work out of it. Change the oil often and see if it improves. Mine got heaps better within a few weeks.

 

[ClemsonCruiser]

Theo, what is SeaFoam, is it something I can get at Advanced, or autozone???? Also, I have only been driving the cruiser for about two months now..... It would be nice if it would just clear up but I am not counting on it.

 

[Desertdave]

When I bought my Cruiser, it had been re-ringed in place by the prior owner. It worked well enough for me for the next 14 years before I put in a rebuilt 2F. The checks the others have suggested will help you determine if it it the rings, or the top end of the motor, that are the source of low compression. If money is real tight, and your checking convinces you that the ring seating is the main issue, then I would suggest that a re-ring in-place is a valid option.

 

[theo]

Clemson, SeaFoam is solvent-based degreaser. I found it at NAPA. I'd guess any solvent-type engine treatment for dislodging gunk would be similar.

I haven't done just rings to my own engines, but I wouldn't hesitate if that's all I thought it needed. .02