4tnv88 Block Heater

[Katahdin]

I was wondering if anyone had a lead for an engine block heater that fits a Yanmar 4tnv88 engine. I'm looking for the screw-in type to go where the plug is circled in the picture. I know these exist for Yanmars, I just haven't see one marketed to fit the 4tnv88. Thanks!

[winston1]

I don't have a definite answer but I believe the ones made for the 3 cylinder Yanmars have 1" npt threads. I know Hoye lists theirs as appx 1-1/4" threads. I also read these plugs can be very difficult to remove and was suggested by one dealer to remove the plug before ordering the heater. My understanding is they have a 1/2" square opening for a breaker bar. If your hole measures appx 1-1/4" I suspect it would fit. Proceed with caution!

[Katahdin]

Yep, the plug was wound in there pretty good. I ended up putting about a minutes worth of propane heat on the plug then tapped it with short bursts from a 1/2" air impact wrench until I saw the plug move. I was then able to easily back the plug off half a turn with a 25" breaker bar, and it does indeed appear to be 1.25 inch plug. Now to get a heater ordered, thanks for the info!

[chriswheeler]

Google a Co. called Kim Hotstart. They make most of the block heaters that almost all of the OEM folks use. Of course they do have the plug type screw in block heater for Yanmar.
Chris

[Car Doc]

I put a Kats freeze plug heater in my 3t84t part number K4NB. I have a thread around here on it from a couple years ago. It was I believe a 30mm but really dont remember that well but its 1500 watt fwtw and it works great they may have a screw in also if you figure out the thread pitch/dia etc. hth

fwtw I see your new tractor has a Nippondenso starter and alternator they are at the top in quality parts anywhere glad to see Yanmar is using them it really doesnt suprise me though.

[Katahdin]

Finally got it done, it was actually a 1 inch NPT plug. The plug measured about 1.29" while still threaded into the block using my calipers, so that threw me off a little, but that's about what the outer diameter of 1 inch pipe is (1.315 to be exact).

I never did find a block heater maker that listed the 4TNV88 engine, but I looked at the Zero Start catalog and saw that their #3100003 model fit both 3 and other 4 cylinder Yanmar engines so I took a gamble that was it. #3100003 fit perfectly and I only lost about 8 ounces of coolant when making the swap as I didn't want to bother with draining the block.



Car Doc, a belated thank you for the insight on the parts Yanmar is using, I do enjoy learning about this machine.

[Car Doc]

Welcome and that looks perfect fit on that engine you will really like it when the temp gets low!

fwtw That starter can be "rebuilt" with a starter solenoid contact kit from Napa part# 655-1143 it will contain more parts than you need but @ $11 aprox it is a cheap rebuild. One contact in the starter on the battery cable side is all that ever goes bad on those starters they are very good starters. The brushes are available from Toyota on the alternators and thats about all that goes bad on them.

[davecharles]

How well does it work compared to a heater in the lower hose. Anyone know what the I.D. is for the lower hose. I want to compare the cost and ease of installation of both.
Dave

[Car Doc]

How well does it work compared to a heater in the lower hose. Anyone know what the I.D. is for the lower hose. I want to compare the cost and ease of installation of both.
Dave

I cant tell you what the hose size is or how for sure a hose heater compares on a tractor but I have had both in vehicles and they both work fine and probably cost about the same. Either one can be a bear if not almost impossible to install on one of our YM's. btdt if you happen to have the block plug that screws in Katahdyn has that one he put on for an instance might help you too!

However my opinion is the block heater is better simply because you are heating the block almost directly rather than the radiator which will radiate the heat quickly and the front of the block even though they circulate to some degree. my .002

[Katahdin]

Thanks again Car Doc, I have the luxury of Yanmar warrantying that starter for the next 5 years, but after that expires its good to know I have inexpensive options!

I would think the efficiency nod would go to the block heater, its already inside what you're trying to heat.

Costs are about the same either way you go, I'm using autopartsandstuff.com for the prices. That's where I bought the block heater.

If you have the tools to get the plug out, I would say ease goes to the block heater, only because if you go the hose route you'll need to drain the block and radiator? I only lost and had to add 8 ounces of coolant.

Here are zerostart part numbers for radiator hose heaters, you just need to match up your hose size:

PART NO. / FITS HOSE SIZE/ WATT
3200001 / 1" (2.4cm) / 375
3200002 / 1-1/4" (3.1cm) / 375
3200003 / 1-1/2" (3.7cm) / 600
3200004 / 1-3/4" (4.3cm) / 600
3200005 / 2" (5cm) / 600

The entire Zerostart catalog is available here: Phillips & Temro - Catalogs It has dimensions on the hose heater sizes if you've got a tight fit.