MTU vs Cat. Diesel

You should probably state which engines you are considering, just to be fair. I m always weary of general blanket statements like cat is better than MTU, or searay than bayliner or ford than Chevy

Personally my experience with cats is limited to 1400 hp 3412Es and they ve been great. Service costs for the 1000 and 3000 hr service has been very low (about $2500 to 3000 per engine)

Considering how many motors they each put out it's hard to compare engine to engine. So sometimes blanket statements are all there is. I've found the maintenance and repair costs considerably cheaper with CATS and service options much more plentiful, at least in the US. Cruising area is something else to consider. In Europe it could be an entirely different scenario. On newer MTUs I've had faults that stopped me, and darned if I knew what the cause was from the display. A short rest and she was going again.
Back in the late 90's I remember CAT putting out some bad motors (I think it was in the 3208 series) and a guy I knew lost one on the way south. CAT had a guy there the next day swapping out motors and had a replacement for his other motor in Miami when he arrived there. I was impressed.

And then there is John Deere, an engine I have been doing some research on. 575Hp

You generally find those work horses on trawlers, sailboats and fishing boats. Not glamorous, but they seem to run forever. I'm not so sure about their marine service representation, but I expect my JD tractor to outlive me.

Hi,

The 3208 is an older workhorse than that.

The troublesome series was the 3176 ad CAT did an exemplary job of repairing many of them out of warranty.

Another less than successful engine from Peoria has been the C9

I worked on a boat with 3208s back in 91 so I know they go back a ways. I could be wrong on the model with the problem though. Word I got was that CAT was under contract with Sea Ray and several other manufacturers and pushed the motors out to satisfy those even though they knew there was a problem on the line. Like you said and my friend experienced though, they were johnny on the spot at taking care of the problems.

Catarpillar lost a few friends among professional boaters (workboats) in Europe during the last 10 years, due to lowering quality and decreasing service. And this counts even more for the bigger MAK engines (Cat company in Germany). We have changed (for newbuilds) to MTU (ironman) and MAN. But for a pleasure boat, to be used in the USA, I would still go for Caterpillar.

We had maintenance on an MTU emergency genset in the USA. They asked a astronomical price for that repair and it took my technical department some blackmailing (unfriendly phone calls), in order to make MTU participate on that costs.

Will say, NYCAP123 is absolutely correct, the area of usage is very important for the selection of the engine manufacturer. That counts for maintenance, price and avaibility of spareparts and labour.

They're great diesels. Parts are reasonable. However their horsepower to weight ratio is very poor compared to others, making them a poor choice for most planing hulls.

MTU tries ANYTHING to try to get out of warrantying a rebuild I had a set of Series 80's, that had 200 hours on them and were under 2 years old and mtu tried everything to get out of paying for new aftercoolers when it was a known problem. Another issues was a rebuild by their dealer on a 12v71 with 3 months and 150 hours on the rebuild......we went back and forth with them for a month while it was getting rebuilt, and the owner ended up eating $14k of that rebuild.

The series from CAT everyone is thinking of with many issues were the 3126's, and one iteration had blocks cast in France that were too weak as well and came apart/split. Cat did end up warrantying all of them even out of warranty.

I've noticed this with quality of replacement parts in the past 2-3 years. We've had a number of injector failures after relatively few hours (one right out of the box), and have had failure of 2 heat exchangers within 1500 hrs of running time.

Hi,

Ken, was this on ME's or Gensets?

I am not a fan of rebuilt injectors these days and would either go for new or upgrade to new.

As for the heat exchangers what went wrong with them?

The material (rubber) at the end-caps broke down, causing fluid crossover. This has happened twice in the past 2 years, although the first time was after about 6 years of wear.

Hi,

Did you by any chance change the coolant when the seals were replaced after the 6 yr run?

If so did you change it to something different to what had previously been used?