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I’m looking to change the engine in a 2003 Ford Ranger with a 4.0 Liter SOHC.
The two best candidates are:
1) An engine with 135K on it $800. The downside is that the engine is not fresh. It was covered with leaves as someone had taken the stock hood partly covered the front of it but left the back where the coil packs are out to the elements. I also noted that someone had written in marker on the hood manifold what size oil filter is required. That signals to me farmer or old man. I’m not sure if writing things on your truck is a sign of good maintenance or a careless attitude towards the vehicle. Vehicle damage was a rollover.
2) An engine with 173K for $600. The engine is covered by a fitting hood and is fairly clean. It has a current oil change sticker in the window. Seems to be a better engine by appearance but looks can be deceiving.
Both engines run… Is the 135K engine worth the $200 extra especially given the time sitting? Is the Ford 4.0 SOHC a solid enough engine that I don’t need to be all that worried about the miles on a donor engine?
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A BIG AGREEMENT on the compression test. The 4.0 SOHC pushrod is a very stout engine. I have seen first hand the damaging effects of an improperly stored junk yard engine. (I am talking caked up mud on the bottom of a spark plug electrode water entering the combustion chamber through the throttle body). I have done several junk yard swaps and I won’t even consider purchasing an engine that hasn’t been kept completely dry
The 4.0 SOHC pushrod
The 4.0 SOHC is not the same motor as the 4.0 pushrod – the 4.0 pushrod was a very reliable engine, the 4.0 SOHC had moderate to severe timing guide problems.
That being said, since one of the biggest issues of the 4.0 SOHC was that the rear timing guide cannot be replaced with the motor installed and it was a common failure part, either way you should replace these components with the engine removed before you install it.
I worked in a salvage yard from the time I was 15 to college years, the yard actually offered guarantees on used engines. Prior to and engine being sold it was compression tested, got at least a new pan gasket and rear seal, was oil primed and any known defects were checked. The place I worked at also stored popular engines inside on big steel racks with info tags on them.
At a bare minimum I would follow the advise others have given you and add changing the pan gasket to the list.[quote=”Masospaghetti” post=117675]The 4.0 SOHC is not the same motor as the 4.0 pushrod – the 4.0 pushrod was a very reliable engine, the 4.0 SOHC had moderate to severe timing guide problems.
That being said, since one of the biggest issues of the 4.0 SOHC was that the rear timing guide cannot be replaced with the motor installed and it was a common failure part, either way you should replace these components with the engine removed before you install it.[/quote]
This is automotive gospel IMHO. It’s going to be between a pricy to expensive repair depending on where you’d be shopping for your new parts. In spite of the expense, it’s worth it to deal with the timing components before you install either engine.
Yes sorry guys I missed the SOHC and just immediately jumped to the OHV engine in my mind. There is a substantial difference.
Go with the one in better condition and that looks better maintained, run compression check and you will have your answer.
Used units are always a flip of the coin unless you can hear it run. Running a compression test is a big plus but it won’t tell you whether or not the crankshaft bearings or timing components are worn out or not.
My unscientific guess is that probably 30% of the used engines, transmission, rear axles I’ve dealt with had problems ranging from at least comparatively minor to outright junk no matter “the guaranteed good” statement from the salvage.
The last “guaranteed good, we checked the internals” rear axle for a Chevy I did had 2 badly bent rear axle shafts and a wiped ring/pinion gear. Took it back and they had another “we just checked this one out for you” waiting for me.
Removal of the rear cover showed the ring and pinion going in that one also.
All of my money back but a lot of aggravation and time wasted.Color me skeptical of claims about condition……. 🙁
Mileage is just a number, especially if they’re the same model year. Go with your gut. It sounds like the extra $200 isn’t really worth it for the lower mileage engine
Compression test, look for rust around fasteners, get a warranty, have them turn it over by hand. This will let you know if there is anything seized up. I am not familiar with the engine but, if you are going to tear it down completely and rebuild it with new seals, gaskets, rings, etc I would suggest thinking about draining the oil and filling the entire engine with penetrating oil till it floods out the intake and letting it sit for a week or 2 like that. There is a possibility if you do this of damaging plastic parts and/or electronics so beware but, it will normally help break down any composites free up bolts, lube the components for easy removal and also show you any hair line fractures in the block, etc. Only do this though if you are going to do a complete tear down and rebuild though.
I actually meant to share these the other day. This is why proper storage of junk yard engines are crucial. This is a Pontiac Sunfire 2.2 Ecotec engine that came from TTG Auto parts in Knoxville, TN they eventually had to refund money as this was the second bad engine. They left the engine sitting outside uncovered water leaked in through the throttle body somehow dirt got down into the cylinders from the intake I am assuming.
If you look closely in the below pic you can actually tell that water sat in the valve cover of this engine for a LONG time, there is a water line that goes across the top of the valve cover. You can see how it angles down in the direction the engine was sitting.
[URL=http://s4.photobucket.com/user/SigSaurP228/media/20140930_095221_zpsce55aaee.jpg.html][IMG]http://i4.photobucket.com/albums/y110/SigSaurP228/20140930_095221_zpsce55aaee.jpg[/IMG][/URL]
This is the bottom of my compression check gauge the very first time I ran the numbers
[URL=http://s4.photobucket.com/user/SigSaurP228/media/20140930_100240_zps62cb6e2e.jpg.html][IMG]http://i4.photobucket.com/albums/y110/SigSaurP228/20140930_100240_zps62cb6e2e.jpg[/IMG][/URL]
Spark Plug as it was just pulled out of the engine.
[URL=http://s4.photobucket.com/user/SigSaurP228/media/20140930_095828_zpsa8ad4530.jpg.html][IMG]http://i4.photobucket.com/albums/y110/SigSaurP228/20140930_095828_zpsa8ad4530.jpg[/IMG][/URL]
THe real kicker is because of the GM ignition rail Coil on plug design you can’t see any of that until you go to pull the spark plugs.
I’d personally go for a lower mileage engine in general. This engine is great. I’ve owned 2 Explorer’s with the 4.0 SOHC and have had 3 Explorers at work with the same engine. One thing you absolutely have to look out for, well…mainly, listen for is the timing chain rattle. A few years ago I had an ’02 Explorer that I bought from a sketchy dealer and it died within a month of a broken timing chain. It was not well maintained by the previous owner, but I’ve had an ’04 for about 6 years now and 160k on the clock and I’m slowly starting to hear the rattle on this one as well. So I’d buy a lower mileage engine or make sure you replace the timing chain and guides before you get it in the truck and it should be reliable for many years.
Mileage isn’t really a major concern for an engine. It does however up the mathematical probability you wont get an engine that isnt running right. First things first Get a breaker bar and rotate the engine at the pulley. It should be able to crank that way. Second take out the spark plugs and look at them and see how the engine is health wise. Once you figured out the Which engine is in better health go ahead and replace the parts that are hard to replace while it is out of the vehicle. Timing chain/belt, water pumps, Belt tensioners and pulleys. Also this a really good time for a tune up to. Replacing the oil,Spark plugs, wires, etc.
Does the price include installation or does the engine come with all the junk like sensors, manifolds etc? $600 and $800 for something with over 100,000 miles is asking WAY too much.
my rules of thumb, engine kept inside where it is dry and warm, engine has fresh clean oil in it and not dirty old oil in it… check for any damp areas at gaskets, see how freely the crankshaft rotates, and a compression test as well, remove the rocker covers see what it looks like inside, if its full of sludge stay away from it, and its good to know the history of the vehicle it was from, also check oil pressure as well, oil pressure is important just like compression.
Another clue besides all the above. Look for an engine from a wrecked vehicle. Why? If you walk up to a vehicle that is not wrecked or rotted out, Why is it in a salvage yard? Usually the answer is bad trans/engine. But a wreck usually means it was running just before it came to the yard. Then it comes down to, look inside a valve cover for sludge/crud suggestive of poor maintenance, Compression test and leak down can tell you some things but bring an oil can along to do both tests dry and wet.
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