Does anybody have any good ideas on how to check the milage on a engine that just bought.The guy didn't have any info on the the motor.On the outside it looks super clean.Took off the intake and exhaust manifolds and there is virtually no carbon in the manifolds.The water passages are really clean as well.The more stuff i took off the better i feel that this thing is really fresh.I'm going to do a compression check on it tomorrow.Are there any checks that i should do before i put it back together and put it in the wagon??
Thanks Mike BTW i picked it up for $100 ;D
I've had engines apart at 50k miles with massive wear and I've had my old 5.0 Mustang block apart at 229k miles that still had hone marks. My opinion would be it's impossible. You can tell proper maintenance by site.
If you can,you might want to do a leak down test.It will give you a more accurate condition of the motor.
Thanks guys,
I have to look up the leak down test it sounds pretty simple.I think this was maintained nicely just because of the condition of the oil galleys and the oil pan no sludge whatsoever.When i pulled of the trans i discovered a brand new centerforce pressure plate and the flywheel looks like it was just machined.Maybe its a pumped mill. ???
It think thats probally wishfull thinking but hey why not.Let me live my dream for now any way.
Ill keep you posted on the tests. Mike
If you're so inclined, and you don't have the oil pan buttoned up yet, you could pull off one each of the main and rod bearing caps and use Plastigage to see what the clearances there measure. Even on an engine with a fair number of miles accumulated, (say up to 100k) if the oil and filter have always been being changed on time, using a decent oil, there should be minimal wear to the bearings, and they should still be within allowable tolerances. Plus, if they are out of tolerance, now would be the time to change them, before the engine is installed.
Without doing a compete teardown, that and a compression plus leakdown test are probably the best ways to tell in what working shape the engine is now, overall.
One more thing: Check out the valve train.
One easy thing to check is to look for shims under the valve springs. Another is deteriorating/hardened valve stem seals. On most engines that have had a decent valve job done, the valve seats will have been machined more deeply into the head, requiring at least some of the springs to have shims to restore the proper assembled spring height and/or pressure, and the valve stem seals will have been replaced. OEM engines generally do not need to have the shims, due to them starting with a raw casting, doing the original machining under very tight tolerances, and using brand new springs. If you DO see the shims, there is good chance that at least that part of the engine was rebuilt. As a rule not many engines need their head(s) removed and a valve job done before 75K miles as a minimum. 100-125K miles would be much more common, with engines of this vintage. Many modern engines can easily go considerably farther than that before needing the same type of top end work.
It would be tough to guess mileage on a well maintained, factory stock engine that has no cylinder ridge wear, for example.
P.S. I'd check the timing belt and tensioner or chain and gears too, if you haven't already done so. If it has a cogged belt and it looks at all questionable, change it now, so at least you will have a fairly good idea as to how long it is liable to last.
Thanks for the replies,
I did a compression test and found out that #4 intake and exhaust where leaking. :wow:
I thought maybe my tester was bad when it said 0 in that cylinder.Since i had the manifolds off.I kind of did my own form of a leak down test.I pumped air into the sparkplug hole when the piston was on tdc.Thats when i figured out that the valves were bad.Lots of air coming out of the intake and exhaust ports,Oh well what do you want for $100.Still got a nice clutch out of the deal. ;D
Pumping air into a cylinder through a spark plug hole when the valves for that cylinder are closed and the piston is a TDC is exactly what is done in a leakdown test. The air pressure is measured as it is supplied (usually via a calibrated gauge) and compared with the amount of back pressure that is on the engine side, (usually with a second gauge), with the difference being the amount of leakage.
in re a compression test:
To be safe and to get a meaningful result, you have to be absolutely certain that the piston is EXACTLY at TDC and that the valves are fully closed. If the piston is only a few degrees off from TDC, air pressure can force the piston down unexpectedly. On many engines the valves may start to open or fully close within a few degrees of TDC, so accuracy is important. If you have any doubts about a pistons' position, (this can happen if the cam to crank timing is off due to belt or chain related problems) use some sort of easily visible, calibrated probe to be sure.
Also, if anything is preventing a valve from seating fully, such as a bent valve stem or head, or a piece of carbon on the seating surface, there will be considerable leakage. Unless you have a good sized hole in piston, a head gasket blown out, a warped head, a chunk of metal missing between the intake and exhaust valves, or a valve that is staying well off the seat or is very bent, having a ZERO psi reading would be unusual. Even having a good sized burned crack in an exhaust valve won't generally drop the reading to zero.
BTW, if the engine has been sitting for a long time, some of the valves may be sticking in their guides from rust or hardened/thickened oil, and may loosen up after the engine has been run or even cranked over for a short time. If this is what is happening, it may be helped along by using something like WD-40 or a small amount of penetrating oil placed on the tops of the valve guides/valve seals, and allowed to sit there, soak and run down along the valve stems overnight. If you still have the manifolds off, you can do this directly.
What sort of readings did you get from the other cylinders when you were doing the standard compression test?
Man goodolboy that is a very through and consice bunch of answers.
You are the man!
The engine did sit for years.And it is definitely possible that there is something like carbon or gasket materail stuck in the valves.When i did the leak down test i had the valve cover off.
I was able to move the the rocker arms freely so I'm pretty sure that they were supposed to be closed.I never thought about them sticking in the guides but know now that you mention it it does make sense.Every thing is of the motor so it will be real easy to take the head off and look at the valves and cylinders.I just haven't gotten to it yet .I'm in the middle of knocking out door dings and small dents on my new wagon.I want to spray it before the 4th of July.Thats my target day to get her back on the road.
I will definitely post on this again as soon as i check it out.
Thanks again MIKE
The morning after you soak the valve stems try this.
Also while you have the air pressure applyed to the cyl...Tap on the top of the valve stem hard enough that you hear a pop.Do this several times. I use a plastic mallet. When you tap on the valve stem or rocker you allow much more air to pass and that may allow the carbon or gook to pass.
When you are using a leak down tester I have seen Readings MANY times go from 50 or 60% leakage down to 5 or 10%. Tapping kind of allows the valve to get a better seal.
Dave