[newtoncd]

We have a 1998 Isuzu Trooper with a 3.5L V6 engine and approximately 97,500 miles on the engine. The rig has been incredibly reliable and up until recently, no problems to speak of....except oil consumption.

We purchased the vehicle new and at about 10,000 miles, I switched over to Mobil 1 10W30 synthetic oil. Ever since new, it has used about 1 quart of oil every 1,000-1,500 miles. While it was under warranty, the dealer said it is "normal" usage, so I continued on adding as necessary.

A few months ago, I got tired of the oil consumption and at about 95,000 miles, I switched over to Mobil 1 15W40. The consumption went away completely; however, there is now a ticking sound when you first start the rig and it is especially noticeable when you first put it in gear <while the engine is still cold>. Once the rig warms up, the tick is not noticeable.

I have changed back to Mobil 1 10W30, but the tick is still there.

Anyone have any thoughts on what this might be??

Thanks.

Curt

 

[JTK]

Hey Curt, I think you are on the right track with thicker oil. IMHO- these engines (1998+) like the slightly heavier oils. You can run up to a 20w-50 at temps above 10degF :shock: . Here's a good write-up from awhile back (minus his opinion on synthetic oil :roll: )

From answerbacker, 4x4wire.com isuzu forum, 08/08/02.

"Here's some info you might be able to use: the cylinder heads and valve train are entirely re-configured in the 98 & up 3.2L's and the 3.5L V6. There are no longer any hydraulic lifters, rockers or rocker shafts; it's a direct attack set-up with shims and buckets, similar to the early 90's Impulse and Stylus 1.6L DOHC. All of these engines have some valve train noise when cold, but in cases where the noise is excessive (and the clearance is too big), the buckets are the problem: the raised button on the underside of the bucket that contacts the valve stem becomes pounded down (it's a hardfacing problem) and actually becomes recessed. Installing thicker shims to get spec clearance back again will not cure the noise for long; the only real fix is to replace the buckets. And in most cases, replacing the buckets is all that's needed, since the shims don't seem to wear at any mileage and the clearance is in specs after the bucket replacement. As far as oil grade is concerned, it's not an issue with these engines anywhere near what it is with the 6VD1's with hydraulic lifters, but stay away from additives, synthetic and thicker grades, regardless of how hot the ambient temp is and how much load you put on it. It's a whole new world these days as far as engine lubrication, and a lot of the advice you'll find worked well 30 years ago, but no more. Also, do NOT install new buckets yourself (don't even remove the cams from the heads) until you know how to 1) lock the antilash cam gear 2) time the cams to the jackshaft and 3) time the cams to each other.
And if you have 59999 or less miles on a 98/99, it's still under powertrain warranty; for '00 & up, it falls under the 10/120K p/t warranty to the original purchaser."

G/luck
Joel

 

[newtoncd]

Any idea how much it costs to fix the noise???

Any idea if I damage is being done by letting the noise go???

Thanks.

Curt

 

[JTK]

No idea on the price of a valve adjustment. I'd guess at about $300+ to check clearances & change shims. A full bucket changeout might be a bit more $$ for the buckets themselves. If your valve lash is far out of adjustment you run the risk of burning valves and pounding away at the valve seats machined into the cylinder heads. If you have too much valve lash, the valves dont stay seated long enough for proper cooling to take place. Over time, the valves will overheat, distort & not seat at all. I would say at near 100Kmi, you want to atleast have the valve clearances checked & adjusted if nessesary. This is also a good time to do the timing belt and T-belt tensioner assembly as well, and possibly the water pump too!!
G/luck
Joel