1998 Cat 3126 Diesel

That is a good engine.

But, at that mileage (and I suspect age) how it was maintained is as important is is the engine manufacturer/engine family.

What kind of maintenance records do you have for it?

My 1996 3126 has 139,000 and didn't miss a beat in the six month 6,000 mile trip last winter. I even ran out of fuel and it started right back up after pumping up the filter. (not recommended)

If you can get the maintenance records and verify that the normal PM has been done, it should be fine. In particular, there's a valve lash adjustment that needs to be done at 30,000 miles, and every 100,000 thereafter. Also,
verify that the fan hub bearing has had regular greasing. I throw a bottle of fuel injector cleaner (Power Service - get it at Walmart) every fifth tank or so.

This engine is normally 250 HP but can be chipped up to 300 and up to 350 with a turbo-charger change.

It always cracks me up when folks say they've HEARD a bunch of BAD stuff about CAT engines. Just exactly WHAT have you heard that was/is bad about the 3126?
Scott

I have owned 4 medium/heavy duty trucks with that engine. All were purchased used and all had over 200,000 when I bought them. All had well over 300,000 when I sold them off. I like that engine, as well as the very similar 3116 Cat.
However, these are not your typical heavy duty Cat engine. They are rather lightly designed and not designed for really heavy service. They also require much better/more regular service than a typical heavy duty Cat engine.
If you can get maint. records, that would be great. If not, check for things such as oil pressure, water temps, and engine blowby at the oil filler cap or dipstick.
One problem with these engines, is that a lot of truck shops are not trained or equipped to work on them, especially the fuel injector pumps. Also, these are generally considered to be "throwaway" engines. They are not rebuildable at an affordable price. If it gets weak, it is best to replace it with a used takeout, or a new engine.
Having said all that, I really liked the ones I had. Very dependable and not bad on fuel use.

The 3126 engine is a very good engine. When new they had a 500 thousand mile or five year warranty. If properly maintained, this engine will last you a long time. The 3126-B has a deep oil pan and holds a lot more oil then the shallow pan on the 3126-E or the C-7 which all have the same block.

Lot of RVer's claim that these engines can not be sleeved, but that is not true. There are kits for installing sleeves if so desired.

Make sure you cool the turbo a little before shutting it down and it should last longer than the house above it.

As many have said, it's not the heaviest built diesel ever, but it's sure not the lightest. It's a good engine with a long history of satisfied owners.

We had one in our last MH, I liked it a lot.

RayChez: I have a CAT 3126E in my 2003 Safari. I am the original owner and it came out of the CAT factory with a deep oil pan! It takes 30 quarts of oil with every oil change. Your statement is not correct!

gswcgi wrote:
RayChez: I have a CAT 3126E in my 2003 Safari. I am the original owner and it came out of the CAT factory with a deep oil pan! It takes 30 quarts of oil with every oil change. Your statement is not correct!

I never heard of a 3126-E with a deep oil pan. The deep pan engine was classified as the B-model.

I will do more research on this matter by contacting Caterpillar.

Thanks for the information.

My boss owned about 50 semi's (single axles used for in town deliveries) all with 3126 CAT Diesels and there was only one bad engine in the bunch! Catapillar recommend to our shop to overfill the crankcases by 1 gallon.

Wow, some info I would NOT follow:

I would love to see anything from Caterpillar (or any other engine maker for that matter) who recommends overfilling the crankcase by 4 quarts. Good way to "rust-proof your toad"

And the shallow vs deep sump could be had on any 3126-- the deep sump was an option. Safari was one of the few who ordered deep sumps.

Shallow sump is stamped steel (i.e. smooth and magnet will stick to it)
Deep sump is cast aluminum (ribbed) and magnet will not stick to it.

Huge difference in capacity-- you need to know which you have!

You could also call the Caterpillar RV hotline with your engine serial number to find out: 877 777-3126.