Somthin strange goin on....any ideas appreciated.

I drove home the other day and some FOD ended up covering the rad for 30 + miles and the temp gauage went to 1/2 for approx 1/2 hour before I figured it out.

since then, on cold starts it takes 7-9 seconds of cranking to get her started. Idles rough for 2-3 seconds then clears up. Starts right away when warm. This is a truck that has started perfectly for over 50000 miles since i bought her.

Gas consumption has apparently more than doubled <img src="/forums/images/graemlins/scared.gif" alt="" />
Still on my first tank stil, but am on my way to getting only 150 miles from this full tank, compared to 260?
Not for certain though.
Checked the oil dip and cap, no strange klingons like i have seen previously from Rad fluid ( blown Head gasket ) contamination.

Thoughts?

Happy New YEAR !!

The first thing I would do is get underneath and see if any wires were damaged by the (off)road debris - I have seen this happen several times (on other vehicles) where the wires to the oxygen sensor get damaged and cause drivability/fuel consumption problems. Also, did you mean something besides 1/2 on the gauge? 1/2 seems normal to me. Anyway, best of luck. Also, I'm new here and new to Monteros for the most part, so there may be an obvious fix that I don't know about.

Nick

Sounds to me like you have water in the combustion chamber / combustion in the water jackets.

This will wet the plugs, and cause hard starting on the cylinders that are damaged, and eventually clear up, and start, but push the coolant out of the radiator.

Head gaskets should fix it.

Pull the plugs to see if there is any obvious sign of water. You may also try to let it sit overnight then turn it over with plugs removed to see if any water squirts out of a plug hole or two. You may need someone to crank as you look. Watch your eyes and wear safety glasses.

While you're checking, examine the plugs for oil - they'll look black. You could have either water OR oil in the cylinders, so until you find the problem, keep an eye on the coolant and the oil - and watch for a puff of smoke on start-up and after a lengthy idle - or on hard acceleration after a long coast.

It sounds like the 3.0L head gasket gremlin got you, but hopefully it's something a bit simpler.

If you indeed find a blown head gasket (compression test should tell you), I'd suggest several things to do in concert with gasket replacement:

1) Check the heads for dropped exhaust guides
2) Check the heads for straightness - have them trued if necessary
3) Have the heads surfaced at a minimum
4) Have the radiator rodded
5) Check/replace the thermostat
6) Check/replace the radiator cap
7) Check/replace the engine cooling fan clutch before you tear down the engine - with a warm engine idling in P, watch the fan while you shut off the ignition (might need an assistant) - the fan should stop IMMEDIATELY with the engine - if it continues to spin even 1/2 turn, replace the fan clutch
8) Replace the valve seals while the heads are off
9) If you do have to replace the heads gaskets, do a search or post back about how to prep a 3.0L block wrt head bolts and threaded depth available for proper clamping range.
10) The FSM is incorrect for head bolt torque spec. The correct spec is 80 lb-ft, hot or cold... re-torque is unnecessary with the OE gasket or Fel-Pro PermaTorque (so use one of those 2 - don't try to save money there).
11) If you have an EGR system, thoroughly clean the upper intake plenum passages with Berryman B-12 (outside and don't sniff)
12) After it's back together and running, check EGR operation and replace any necessary parts.

Good luck,
Frank

Great replies guys, thanks for the unput. I'll check the plugs n such, and go for a compression test.

My temp gauge usually runs at 1/4, with 1/2 only showing during idle during summer.

Wasn't near much watr, so think that rules out water contamination.

Does Blown H Gasket affect fuel consumption?

Yes.

Water contamination comes from the cooling passages in the head with a blown head gasket - same for oil.

Keep an eye on the oil and coolant when it's hot - coolant in the oil looks muddy tannish/brown and sometimes frothy. Oil in the coolant turns muddy also - with froth and sometimes clumps of goo. Either one of these is bad news - result of head gasket failure, a cracked head or a cracked block.

Frank

It's been like ten years since I've seen one, but I have bought a chemical kit for like $30 or $40 (I think at NAPA?) to test for exhaust gas in the antifreeze.

Yep, I have one. It's in the back of my truck right now. I took it to Hollister to test Ray's truck but I forgot about it.

Clay

Look at the ecu coolant temp sensor, too. Ecu may think the engine is cold and be dumping lots of fuel. Should smell it in the oil.