OK... Here Goes: Cat 3120 w/ Allison -- to buy or not to buy?

SkoolbusLife · 01-22-2021, 10:51 AM

You can probably tell from the question I am new to this game. I'm not a mechanic so I have no idea what is good and what is not, so here I am.

I have a bus in my sights that simply needs a new radiator - fine. However, is it the right bus for me and my needs? No idea. The body style is exactly what I want.

Engine: Cat 3120 engine (from the current owner's statement)
Trans: Allison (not sure what series, I haven't seen it in person and the owner does not know)
Mileage: 205K
Length: 24'

Outside of the radiator issue, the owner states everything else operates perfectly.

Any suggestions?

musigenesis · 01-22-2021, 11:46 AM

There's no CAT 3120 engine but there is a CAT 3126 which is a good engine. As far as only needing a radiator, I wouldn't trust a seller who doesn't even know what their engine is. Unless you're a mechanic type yourself, you should really start with a bus that is running normally.

SkoolbusLife · 01-22-2021, 12:06 PM

I appreciate the response.

It seems there are mixed reviews on this engine so I'm looking for a little more clarity.

The gentlemen selling the bus was going to convert it but found something smaller so he's not overly familiar with it either.

I'm about to go look at and will post the results and maybe get a little more clarity on it.

Thank you!

musigenesis · 01-22-2021, 02:08 PM

https://www.youtube.com/watch?v=IA45...l=DEBOSSGARAGE

s2mikon · 01-22-2021, 03:42 PM

If you know your shoe size get a pair of nike running shoes pronto.

Ronnie · 01-22-2021, 04:58 PM

Why does it need a new radiator? Is it leaking, or overheating? If you and the owner are not mechanically inclined there could be a lot more to this story then either of you realize. I would say pass on it unless you can get a mechanic to look it over and one that is familiar with Cat engines.

Oscar1 · 01-22-2021, 06:04 PM

Hello George and welcome to the group.
Sorry for your troubles but it sounds like you've got a great attitude and a plan to move on. Cheers on that.
I think you can start to see a pattern emerging here with the responses, while you may have construction experience to help you through your build it sounds like you might be lacking a bit on the mechanical/commercial vehicle side of things. As others are saying this might not be a good start for you, being that the owner actually has very little knowledge of its condition and why it needs a rad. Your reference twice to it being a 2120 engine means you've done very little research so I'd suggest you slow down, stay involved in this group and study hard before that big commitment/purchase, it's not easy to get out once they pull you back in. If he's selling it because he's realized he wants something smaller then he to to rushed in to the purchase. Also if he didn't blow the rad why did he buy a broken bus?
Good luck with your search and stay positive, it'll happen.
Cheers

Oscar

DeMac · 01-22-2021, 07:01 PM

I've been here more than once.
"Only needs a _____." ....to find out what else is wrong with it.

What is the asking price?
You may get different responses if it's $500, for instance.

If the price is low enough, it may be worth your time, not money.
Offer to install the rad, at no cost. He buys the part for his vehicle, you install it in good faith. If you still want to buy it after the repairs are completed, you pay a previously agreed upon price, plus the cost of the part(s). If, in the process, you discover more problems, you share those with seller and can back out or renegotiate.

Buyer: Must complete rad change.
Seller: Must honor to sell, no upping the price or backing out.

I've finished both ways.
Bought a non running truck, plus parts reimbursement to seller.
Also, changed (not bought) a master cylinder for free, then walked away.

No loosers here.

Even if you don't know how to complete the rad change, just know that you CAN do it. It's quite simple, really, even for the first timer.

Good luck, whatever you decide.

rossvtaylor · 01-22-2021, 08:19 PM

Good comments so far...of course.

There's nothing inherently wrong with the 3126...it's a good engine, on par with the others mentioned in the video. The video title makes it sound a bit like an "oh no, stay away" exposé but if you watch it you'll see that it's really not different from other mainstay diesels...they each have their issues.

My biggest concern here, really, is the radiator issue. I'd be concerned that the seller overheated the engine, which will kill them (not just the 3126, but any of them), and blamed it on the radiator. "Sure, it overheated coming up that long hill...and quit running...but all it needs is a new radiator." So...as you say...it may simply need a new radiator. But that makes my spidey sense all tingly.

s2mikon · 01-22-2021, 09:08 PM

The radiator issue should be a RED FLAG. These engines are not wet liner engines and if the bore is ruined you have to pull it and bore it. This is not cheep. A DT466 is a wet liner engine and is in frame rebuildable. Same with the 8.3 Cummins. Look up changing the timing on the Cat. The International DT466 and Cummins 8.3 is easy to tune and change timing. So be very very careful.

EastCoastCB · 01-23-2021, 10:18 AM

3126 is a great engine. But dont buy a bus that "need this or that" mechanically. There's usually a much larger repair under that "tip of the iceberg".

rossvtaylor · 01-23-2021, 10:28 AM

So, did you go look at it? What did you find out? Curious minds want to know...

SkoolbusLife · 01-23-2021, 01:00 PM

OK... so this will be the third reply. The system's session cookie seems to log me out as I'm typing and then fails to complete the post upon submitting and re-logging under Safari.

Let's try Chrome...

SkoolbusLife · 01-23-2021, 01:29 PM

First of all, thank you for everyone’s participation. I appreciate you spending your time on helping me out and answering my questions.

The video was fantastic and very informative. Unfortunately I did not see the video prior to going to see the bus; but more on that in a minute.

Since watching the video, I’ve been looking at buses non-stop and taking in the various engine types out there that people are using in their rigs. There’s a lot of of mixed reviews on the same engine (of various types) so I’m trying to weed through all of that by taking notes and getting an overall understanding for my situation. I’ve also been asking about the HEUI hose. In many of the images taken by the owners, I can see that most have been changed.

I’m going to be all over the country in this bus, therefore, I would like to make sure that whichever bus I choose, it needs to have plenty of hill climbing power and descending assistance; although I understand speed plays a big factor in the descent as well.

I’m not currently going to be pulling anything in the way of a vehicle. I currently drive an FJ Cruiser and I will not be taking it with me; however, in the future, I may get something small for in-town travel so having the power to do so will be key.

I was going to go with a shorter bus originally, but now after seeing so many conversions, I may want to stick with the longer bus — I’m not always going to be alone so if some special decides they would like to take the journey with me, there will be plenty of space for growth; albeit, I’ve seen some really nice short bus conversions that couples live out of.

If you all have any advice on sizes, I’m open to that as well — perhaps not the place for it here in this thread but I’m going to throw it out there anyway.

OK, so, as I mentioned above, I did go and see the bus; I did not look for the HEUI replacement because at that time I was not aware.

The girl that owns the bus bought it from the original owner who used it for her local school district until last year. The bus fired up nearly immediately after 3 months of sitting there. I arrived before they did and the engine had not been started; at least not before I arrived.

The issue with the radiator is still unknown as she could not articulate what her mechanic told her. She simply stated that she brought to a mechanic and they said it needed a new radiator. I looked around the radiator and did not see any issues with leaking, and I also looked at the temp gauge and did not see any issues with heating so I’m not sure what else there is to it; obviously there is something though.

The bus didn’t produce any white smoke when revving and things otherwise seemed pretty tight. What threw me off a little was there were signs of grimy oil seepage on the engine block and other areas, but nothing appeared to be leaking — no dropping and no signs of oil on the ground. Would this be common in high-mileage vehicles like this? I have no idea.

Another thing that threw me off was that it’s peak horse power (indicated on the engine plate) was a max of 207HP; this to me seems like it wouldn’t do very well with hills but it’s a short bus so maybe it would, again I have no idea.

Long story short... I am not trying to buy someone else’s headache, although, there is always the off-chance that may happen. Like most others, I’m just trying to make an informed choice while being mindful of the fact that it’s always a possibility.

Thank you all for the continued education on this! I need it.

Jolly Roger bus 223 · 01-23-2021, 02:12 PM

ok 207 HP is a weird number but my big bus and alot of busses are in the 175-195 range.
it setting there at idle might not overheat it unless there is a real problem with the radiator.
get an IR temp gun.
does this bus have the split radiator with the tranny cooler involved also?
did you get to look at the transmission as far as ID,model,serial?
sounds like it needs a good test drive and not just an inspect at idle.
needs a radiator is a shop without leaks sounds like a shop that knows they have someone who doesnt have a clue and they are parts changers until the problem is fixed.
talk to the owner and see if they took to the shop because they had problems with it overheating or if they wanted it checked out?
why was it in the shop?
when i say test drive i mean more than just a mile or two around the block.
sure idle it, walk around inspection for air leaks and tire stuff then hit the road for a little while because thats what you are buying it for.
if the seller has a problem with that then tell her to drive it.
can not always trust the dash guage.
if it starts to overheat then stop and take your IR temp gun and read the hoses in and out of the radiator and then the radiator.
if it has the split radiator then read each one seperately. a transmission that needs attention with a split rad can raise the motor temps.

Ronnie · 01-23-2021, 07:42 PM

If you want to look into this bus some more, I would look in the radiator and see if it is full or not, and what does the coolant look like. Should be some color, but with real clarity. Cloudy but colored( green or orange is common) could just be old antifreeze. If it looks like pea soup run fast....could be an oil cooler, head gasket, o rings on the liners. A mechanics special.

You could also buy a radiator pressure tester and put some pressure on it. I pressure test to what the radiator cap is set for. It should say on it. With pressure you should be able to find any leaks if it leaking.

Ronnie · 01-23-2021, 07:44 PM

Oh if it has a split radiator that is one half radiator and one have cooler, these do not do well in the mountains. you want a full radiator for mountains.

SkoolbusLife · 01-24-2021, 08:11 AM

Quote:

Originally Posted by Jolly Roger bus 223

ok 207 HP is a weird number but my big bus and alot of busses are in the 175-195 range.

Perhaps I misread the label, it appears you are correct.

@Ronnie, thanks. I'll have to take a look at the coolant and see what it looks like.

P.S. Thank you guys for aiding me in this endeavor. I appreciate you.

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