eric147

It looks like I'll be replacing my water pump on my 1997 Rodeo 3.2L.

I have a repair manual on order. At 120K, this should be a good time to replace the timing belt, and I'm assuming having to get at the water pump will expose most of this anyway.

I should also replace the spark plugs, oxygen sensor...Anything else?

Also, while I'm here, my FWD has not worked for a year. It went through stages where it would sometimes work. Particulalry, if I drove someplace, turned off the motor, shifted into 4X high, left the motor off for an hour, then started it up, it would go into 4x.

That stopped working after a while, and now it just doesn't go in at all.

Vacuum leak? A bad switch somewhere? Serious mechanical?

Any input would be most appreciated.

Thanks

Eric

rodeo02

Eric- 120Kmi is a good point for some major maintenance. T-belt, T-belt tensioner and water pump should all be done at the same time while you have the front of the engine apart. Keep in mind though, that these engines are non-interference, so if the belt were to jump off on you, the truck would just stall out with no damage to the engine. I would personally wait until the T-belt tensioner starts to knock or the water pump starts to leak before I tore into it. I've never seen a T-belt fail on the 3.2 or 3.5L (never changed one either!) Only use NGK or Denso replacement spark plugs. Since your truck is a 1997, I think you have 3 to 4 O2 sensors. I would replace the ones upstream of the cats if you are getting bad MPG's or performance issues. As far as the 4x4 issue goes- I'm not all that familiar with the 1997, but IIRC, you have a floor shifter to shift in/out of 4x4? Either way, you have an electric SOTF motor on the drivers side of the front axle. That is usually the cause of what you describe. Check this link: http://www.planetisuzoo.com/articles.htm/65
G/luck
Joel

eric147

Thanks for the input, Joel.

Hmmmmmmmmmmmmmmm.........................
When I was checking into getting the Tbelt changed at 60K, the shop told me I'd better, 'cause if it jumped, it would do thousands of dollars worth of damage.

You don't suppose they lied to me??!!?

I'm sure my water pump has failed: The thermostat is good, the motor gets hot (overheats) and the heater blows cold. I could smell radiator fluid for a few days before it overheated. If I have to tear through the timing belt/tensioner to get at the water pump, might as well replace it.

I have a floor shifter for the 4WD. I'll check the SOTF module.

rodeo02

That shop probably didn't "lie" they are just mis-informed. Most have VERY little experience with the 3.2L. It is a non-interference engine. I doubt your water pump is bad & not circulating coolant. If it was, your engine would have cooked in no time. An all aliminum engine like this will crack/warp a cylinder head, or split the block in no time if it overheats. I would suspect a clogged or dirty radiator, cheap aftermarket thermostat is no good (only use genuine isuzu t-stats), or your cooling fan is not doing it's job at low speeds or idle. Beware that you are overheating your tranny every time your cooling system gets too hot!! There is an ATF cooler in the bottom tank of your radiator. The 4L30E is costly & troublesome to fix or replace.
G/luck
Joel

eric147

I didn't drive very far when she overheated. And I could smell radiator fluid a day or two in advance of it overheating.

Can I check the water pump by removing the thermostat, and checking flow through the radiator with the cap off and the motor running?

2eyefishclaw

how low on coolant were you
I would almost be willing to bet your waterpump is leaking and low coolant level caused overheating

I personally have never seen an Isuzu thermostat stay stuck closed they usually stick wide open when they go, but it is possible to stick closed

what the heck you have enough miles on it replace it
check for coolant dripping from the front of the engine you can not see the water pume without removing the timing cover

and if you are going to replace the water pump the timing belt must come off so definatly replace it unless you would peffer getting left on the side of the road (SOON) also this is a big one DO NOT PUT THIS THING TOGETHER WITHOUT A NEW TIMING BELT TENSIONER if you do you will regret it

and to your previous question sure try it out

2eyefishclaw

or just boil your thermostat to see if it opens

eric147

"Keep in mind though, that these engines are non-interference, so if the belt were to jump off on you, the truck would just stall out with no damage to the engine. "

Joel-
I just got my Haynes Repair Manual. Chapter 2 Part D 3.2L V6 Engine on page 2D-5, regarding Timing Belt Removal, Installation and Adjustment states:

"Caution: These engines are "interference" engines. This means that if the timing belt breaks, valve and/or piston damage will probably occur."

??

rodeo02

Haynes manual is riddled with errors, always has been. Just to prove the point of non-interferance, there's an owner on the edmunds rodeo board who just had a shop change his T-belt on his 2001 rodeo @ 60Kmi . (precision auto / chain type place) They had one of his cam pullies 180deg off & didn't know it. This guy drove it for a few days & the truck just ran really rough. An isuzu dealer had to resolve it for him. Plus, some guys on the 4x4wire isuzu board did their own T-belt changeouts on 1998's & had the valve timing off as well (on thier first try) with no damage what so ever. This is the only real life data I've been able to find, to get the true interferance/ non-interferance answer.
G/luck
Joel

cheekbn

Just chimming in here... The Haynes manuals are not worth the paper they are printed on... Only trust a Chiltons (have to order from a book store) or the actual shop manuals. Just my .02 worth... and yes this is a non-interference engine as stated before.

Brent

2eyefishclaw

these engines are considered by Isuzu to be interferace engines but I have never seen bent valves on one of these

eric147

OK.

Thanks for the input!

How 'bout this one:

Is the crankshaft pulley bolt a left hand thread?

eric147

I have had one person suggest I brace the breaker bar against the frame and bump the starter to loosen the bolt.

What say you?

rodeo02

Yep. Either that or clear everything out of the way so you can fit an impact gun in their to remove the crank pulley nut. I've heard several reports of the breaker-bar & starter trick doing the job very well on these trucks. No casualties or deaths either .
G/luck
Joel

eric147

I could not bring myself to bump it with the starter.

Luckily, a 3' pipe wrench and a 4', 400ft-lb torque wrench did the trick.