I have already read through these forums looking for answers to my rough running problem and will update and then ask for advice on how to proceed.

The vehicle is a 98 Ranger Sport 4x, 4 liter engine, auto.

This past weekend my temp gauge headed up toward the red. Natch I pulled off the freeway and checked under the hood. The radiator was cool, the hoses to the engine appropriately hot. Strange. Still, I switched to my G Friends Honda CRV and went to the day of wine tasting. Ummm. On the way home the truck ran worse but the temp gauge was and remains normal.

I found my way here though googling and learned about coolent temp sensors. I had already bought a t-stat. I took advice I read here and disconnected the sender and the ride improved. Still it wasn't right. I pulled into Autozone and loaned and helped to run the computer diagonosis. That led to two codes. P 0118 + P0304. 118 said it was the coolant temp sensor too hot. and the 304 said it is the # 4 cylinder misfiring.

This is where I need advice. I presume the misfire at this cylinder means the plugs, wires, and injector in addition to any possible cylinder leak. (The Autozone salesman said I could have a crack in the cylinder.) I like the spark option much better but I know I don't have a choice.

Am I right to go ahead and inspect the plug and change em all if that one is bad? I haven;t done plugs since I bought it at 78,000 and it's now 105,000.

Is there anything unusual about removing the plugs or is it just the same kind of difficult access as my former GMC Jimmy V6? Hey, I'm driving a ford now and this babies had zits compared to that GM's heart attacks.

 

Keep in mind that the P0118 code will set if the ECT is unplugged, which you said you did.

Have you changed the T-stat yet?

The misfire code is the one I'd worry most about. Maybe try a new plug just in that cylinder and drive around for a while. If the misfire persists, try swapping the #4 plug wire with another one and see if the misfire follows the wire. Hopefully it's not a problem with a head/intake gasket.

P.S. Welcome to FTE.

 

Thanks Rockledge. I did replace the sensor but I have not changed the t-stat. All the physical signs now are that it's OK. The engine block and hoses are appropriately warm and the gauge reads perfectly normal. Of course now, as I type this I recall that the hose on the top right of the engine comartment from radiator into the t-stat housing was "flat" as in a curved rectangle, like it was sucked in, when I first went to work on it this morning.

As to the cylinder. I bought a set of plugs and was going to change number four but crank as I might I could not get the plug out. Do the garages put these things in with power wrenches? Or am as old as I look? Any suggestions? I appreciate the suggestion to switch the cable as a test for that, but how will I know if it is the cable, the truck will still run rough just on another cylinder?

I'm curious about your user name, why rockledge? Anything to do with climbing?

 

You changed the two-wire sensor (ECT) and not the single-wire sensor (temp. sending switch), correct?

You really ought to change the T-stat.

Sometimes the original plugs can be hard to break free. Don't be afraid to squirt a little penetrating oil down there and let it soak for a while, then give it a shot. Might be easier to do when the engine is a little warm (but not hot).

If after you change the wires around you still get misfiring, then I suppose you'd have to get the codes pulled again to see which cylinder is at fault.

If you bought Bosch plugs, bring them back, they don't work well in Ford DIS/EDIS ignition systems.

I'm in the real estate business (self-employed). Rockledge is the name of my company.

 

Welcome to FTE hotpop.

On the plug wire, you could try doing a end to end resistance check, it should be approx 1000 ohms per inch of length, 30,000 ohms max, whatever the length.
If it's out of tolerance high, it could cause a weak spark that blows out & cause a misfire on that cylinder.

Hopefully it isn't a head gasket problem.
Observing the recovery tank coolant level, are you showing any signs of slowly loosing coolant, or showing any signs of coolant being in the oil, or any bubbles in the coolant at the radator, with the engine at idle????

On the radiator hoses being sucked flat, I had the same problem with my then brand new 99 4.0L.
Dealer found that the plastic coolant recovery hose. between the radiator & recovery tank, was improperly routed under the air box & was pinched shut, such that the cooling system couldn't equalize during cool down & would cause the hoses to collapse, properly re~routing the hose fixed her up, so check yours out.

Let us know what you find.

 

Thanks again:

I'm here in sunny and warm Calif. Finally after weeks of rain and now this weekend I have to go to the East coast where I here it's chilly. Point is I'm reading replys at 9AM PCT.

Will the P0118 code be off if you reconnect the ECT before running the diagnostic? That's what I did. It was $18 and change and easy to install, plus it runs somewhat better so I think it's good I did it.

Haven't done the t-stat. I am keeping an eye on it and have one from the parts store ready to install.

The water in the compression chambers was what I had with that Jimmy. What a nightmare (another story) so I did check the dipstick and the coolant levels. Oil is clear and levels are right. This truck does not leak one drop of any fluid. First vehicle I've ever had like this with this mileage.

Thanks for the tip on the lubricant for the plug. I'll do it. I have a 3/8" drive and it's a long extension so I think I lose some torque and I know I've lost some torque in the fleshy parts.

The codes said it is the #4 misfiring, so I am doing that first. I'll also give the Ohm test a try on the plug wires. Update later. I may not get this done till I get back from Virginia. Lucky, that I can take public transpo to and from the airport. In LA, who woulda thunk?

 

Oh yeah I did change the two wire sensor. Funny about the Bosch. The salesman recommended them but I asked for what Ford recommended without a clue about the Bosch. Sometimes being called the best is just hype, eh?

I got autolight plugs.

 

autolites are good. since you have a radiator hose sucking flat, make sure you replace both upper and lower radiator hoses.

 

Let's put it this way: If the P0118 were the only code, then the CEL would go off once you reconnect the ECT to the harness, however, the code itself would remain pending in memory until a few "drive cycles" had been completed.

 

Update and new issues with the temp gauge issue.

I've been out of town twice and that addled my also busy schedule so it's taken a while to get back to posting the work I've done on this. I did replace the # four cylinder and the truck immediately ran better. My temp gauge still showed up in the higher ranges. So, I did replace it. Then I only drove a few short trips but up to 35 miles with no problems. All good I thought until I drove down to San Diego this past weekend. Traveling in slow to moderate speeds my gauge would begin to creep up to close to the top - but when I started going 70 on the freeway the gauge would drop back down to normal running range.

I still have no indication of running that hot in the engine compartment and no steam, etc... Fan spins normally, the belt appears to function perfectly and is in V G condition. When I came back from my first trip to the East Coast I thought I saw a very small amount of water just in front of and in from the front left tire but not since (perhaps it was from rain dripping through due to parking in carport).

I wonder if my coolant fluid is low but my manual says to fill overflow to the mark and I am unable to see a mark on the overflow tank. The tank is half full of coolant.

I did not change my thermostat since changing the gauge seemed to resolve the problem initially. I'm looking for suggestions. Could the higher speed cause the water pressure to push the thermostat more open and improve flow making the temp come back down?

Looking forward to reading your replies.

 

What did you find the problem was with the radiator hose being sucked flat???

 

Don't ignore the flat upper rad hose. That is a sign that the system cannot equalize pressure inside the cooling system. It has pumped out, through expansion, some coolant to the overflow, and now wants it back... but no go, so it just contracts the coolant as it cools, and ambient air pressure collapses the hose. You DO NOT WANT the coolant level to be low. Cylinder heads on the (all, apparently) Ford V6 engines are prone to cracking when they get overheated. The first time. So, if the $5 thermostat in the glove box is still in the glove box when it overheats, it won't do a lot of good. Save a bunch of $$ and check it out before it gets hot.
tom

 

The flat hose had on every visual inspection since it first was flat maintained a normal round condition. It has not appeared flat at anytime since.

 

that's good news. you don't have a vacuum problem, then. t