My '06 3215HST with about 45hrs on it did something strange today. I was doing a little bit of front loader work today for about 10 minutes. Then I stopped the tractor, lowered the rpms, put on the parking brake and got off to close the gate. When I got back on the tractor I brought up the rpms again but noticed that the tach was reading about 3000rpms. The engine didn't sound like it was running any where near that hi though. I pushed the trottle down to idle speed but the tach was reading about 2000rpm and stayed there. The tractor engine was definately running at idle so the gauge was obviously off. I turned the engine off and restarted it and the gauge started reading correctly again and seemed ok the rest of the day. Any thoughts on what to check in case it happens again? Thanks.
tach reading wrong on 3215
- Thread starter MrChris
- Start date
BobG_in_VA
Veteran Member
- Joined
- Jul 4, 2003
- Messages
- 2,002
- Location
- Central VA, USA
- Tractor
- Mahindra 6000 MWFD, 2 1950's Farmalls, 1974 Farmall 140, 1967 Mf 135Delux
MrChris said:
Just guessin' here, but since (I believe) the tack is electrically driven, you must have had an electrical spike or something like that. Once you shut it down it reset itself. I wouldn't worry about it unless it becomes a habit with your tractor. I've noticed that sometimes when I first start my tractor that the tack sits on "0" for an instant after the tractor starts untill the voltage comes up to required levels. BobG in VA
Thanks Bob. I'm gonna keep an eye on it. Thought there might be a loose wire or connection, but I would think the gauge would read 0 at those instances or at least fluctuate. What I experienced was the gauge being steady at the 3000rpm and then went down to 2000rpm and stayed there when it should have been reading around 750 idle rpm. I like the voltage spike suggestion. I'll let you know if it happens again or maybe more consistently.
Well, my 3215HST is having the problem again with the tach. I noticed today that if I raise the rpm to near or past the 540rpm indication on the tach, which I believe is about 2376 rpm, the needle pegs up off the scale and stays there until I lower the rpm, but will not read lower than 2000rpm even with the engine at idle. Also if I shut off the engine and restart right away the needle still indicates incorrectly. However if I shut down for 5 minutes or more the tach reading seems to correct itself until I raise the rpm to 2376 or higher. Any new ideas on what's up? Thanks.
My tach has still been giving me intermittant problems so I called my dealer to come pick up my 3215 for service before my warranty runs out the beginning of Dec.. At least I think the warranty is gonna run out. The warranty paperwork I got with the tractor says the 3215 has a 1yr/1500hrs bumper to bumper warranty and then a 3yr/2000hr on the drive train. The service tech seems to think it's a 2yr bumber to bumber. I hope he's right but just in case!
I did have a chance to look closer at how the tach is driven and it appears it's mechanical not electrical as some people have mentioned here. There's one cable that runs from the engine to the tach. It looks like an atv brake cable. There's a wire inside which I assume spins at whatever rpm the engine's at and then turns the tach. Both ends appeared to be properly attached both at the tach and the engine so my guess is it's messing up somewher in the tach or inside the engine. The tech said he rarely sees mechanical tach failers, much more of the electrical with poor ground connections and such.
Anyway, I dettached the FEL today and she's ready to go. I'm curious to see how long it takes to repair especially if they have to order a part. I'll keep you all up to date.
I did have a chance to look closer at how the tach is driven and it appears it's mechanical not electrical as some people have mentioned here. There's one cable that runs from the engine to the tach. It looks like an atv brake cable. There's a wire inside which I assume spins at whatever rpm the engine's at and then turns the tach. Both ends appeared to be properly attached both at the tach and the engine so my guess is it's messing up somewher in the tach or inside the engine. The tech said he rarely sees mechanical tach failers, much more of the electrical with poor ground connections and such.
Anyway, I dettached the FEL today and she's ready to go. I'm curious to see how long it takes to repair especially if they have to order a part. I'll keep you all up to date.
RedRiver
Gold Member
It is a 1 yr. bumper to bumper warranty. I have seen some problems with instrument panels and the guages either reading incorrectly or not working at all, although I have not seen any on the 3215's. Definitely make sure the dealer gets it addressed before the warranty runs out.
Unfortunately I date back to the time when all tach's were mechanical.....It's usually a cable problem. Sometimes the inner wire has a hard spot, a kink or a twist......The outer housing probably has some sort of lining (teflon ) and if it's damaged it will cause sticking and jumping.....If the head is bad be SURE to get it replaced under warranty. Instruments can be really expensive.......
allenr
Gold Member
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- Nov 28, 2006
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- 399
- Location
- Barossa Valley, South Australia
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- Duetz DX3.70, Fendt 305LSA,260S & 205P,Kubota B6100E & 3 x B5100E & RTV900, Caterpillar 428C
Really expected it to be an electronic tachometer.
I have an electronic tachometer on my Caterpillar 428C and it reads just about anything it wants to!
Never known a mechanical tachometer to behave like that although I have one on a Fendt tractor where the needle has somehow got past the little stopper thing and so stays there permanently.
Have tried to lift it back with a magnet but to no avail.
I have an electronic tachometer on my Caterpillar 428C and it reads just about anything it wants to!
Never known a mechanical tachometer to behave like that although I have one on a Fendt tractor where the needle has somehow got past the little stopper thing and so stays there permanently.
Have tried to lift it back with a magnet but to no avail.
bill6
Silver Member
....I still think it IS an electronic tach. On my 3215 I replaced the whole instrument panel twice, due to the hr meter quitting. Yes there IS a long cable, but though it seems strange, I think this cable may be for the hr meter only? I'm not completely sure; but my dealer called Mahindra several times and they always told him the tach was electronically driven. I think Dave and Rob @ Dave's Tractor may know for sure.......
I didn't think about the cable contolling the hour meter? There is a small access panel that snaps out on the top front of the instrument panel housing. I was able to look inside and stick my hand in and check the cable connection at the tach. I loosened the cable set collar and tugged on the cable and the tach needle was affected. I didn't want to mess with it too much since it's still under warranty, but that was enough to convince me it was controlling the tach. I coudn't see any other wires, electrical or not leading directly to the tach, but there are wires and wire harnesses in that area. I know there is backlighting and other guages in the instrument cluster so maybe the wires feed into the tach from some other part of the instrument panel. It's so nice to be unsure. I'm gonna check with the dealer later to see if they had a chance to check it out yet. They are short handed with techs alternating attending some type of schooling this week. It may not be looked at till Monday. Check back with you all later.
I'm gonna check with the dealer later to see if they had a chance to check it out yet. They are short handed with techs alternating attending some type of schooling this week. It may not be looked at till Monday. Check back with you all later.