'95 Aerostar 4x4

[Gen]

We just bought my wife a '95 Aerostar, 4.0, 4x4. Seems to run well. Has a noisy power steering pump. The problem we are having with it is the check engine light comes on whenever putting a load on it, mostly going up hills. I took it to someone and they tried pulling some codes off it but none came up. I notice there is a LOT of detonation while driving a low to medium RPM under load to get the light to come on. Would the decarbing procedure help out with this? Anyone else have this problem?

Thanks,
Gen

[copper_90680]

Hi Gen,

Welcome to the club

You should first try to get the code. For 1995, you have OBDI so the procedure pinned to the top of this forum should work. Try reading the code from the flashing "Check Engine Light" instead of a voltmeter.

[bertha66]

Welcome to the site. Decarboning the engine would not hurt it. My van was give me a random code that would not come up on a computer, mine turned out to be the HCT senser was making it run rich and carboned up the O2 senser.

[VanGo]

Welcome!

Good luck with the pinging problem. I've tried several things over the years and can't get rid of it. I may look at this HCT sensor.
Rebuilt P/S pumps range from $60 - $160. You will need to rent a special pulley removal tool to change it out.

[Gen]

Thanks guys.

We used a Snapon reader to try to get the codes. I'll see if I can get them another way.

What is an HCT sensor?

Thanks,
Gen

[taurus8]

Re...the power steering pump. I was told that when they get old, they get noisy. I've noticed this on other Fords as well. I had my mechanic change the seals as he checked it over and said my pump was fine.

[bertha66]

Originally Posted by Gen

Thanks guys.

We used a Snapon reader to try to get the codes. I'll see if I can get them another way.

What is an HCT sensor?

Thanks,
Gen

Heat control senser, it's on the intake, drivers side with a 2 wire plug, I think it's a 2wire plug, treaded into the water jacket.

[96_4wdr]

aka as an ECT
Ford Fuel Injection » Engine Coolant Temperature Sensor (ECT)

do a flush and clean on the ps. search aero forum for directions. use a full synthetic Mercon ATF such as Mobil 1, expensive but has long life. requires 2 qts min. to clean all the old crud out. if the new ATF blackens up after a couple days, reflush. put a can over the ps pump filter tube to stop rain water intrusion.

you will get CEL flashing with predetonation pinging. PCM sees it as miss firing. may not set a code.
do the decarbon treatment listed in sticky threads. use Berryman's B12, cheaper than the Ford stuff and has same ingredients. may have to do 2 cycles to get all the carbon out. let set at least an hour to soak after flooding the engine with the cleaner.

old worn wrong app. plugs can also cause pinging. check the plugs. Motorcraft or Autolite double platinum only in the EDIS 4L or EDIS 3L. almost anything will work in the distributor 3L.
if plugs are worn then time for new ig. wires also. they cook under the tight compartment of the Aero. again use only Motorcraft, Autolite or AC Delco 8MM silicones direct fits, no universals and lots of silicone ig. lube on boot connectors

[VanGo]

I think the HCT (also called an ACT air charge temp on the intake I believe) and the ECT are two different things here. I replaced the ACT and it didn't help.

[96_4wdr]

a failed Engine Coolant Temp sensor usually shows up as a rig that idles too rich hot or many show up as a difficult to start cold.

[Gen]

I have noticed this thing always registered on the cool side. Even while loaded up and driving in 90+ degree weather, needle never got above 1/4 on the temp gauge. Maybe the temp sensor is the culprit.

[96_4wdr]

normal for the Aero. just an idiot gauge like the oil pressure
Ford designed them for soccer moms with no mechanical brain.
Cool = Better.
High Pressure= Not Good.
Ford got tired of women running to the dealer shops with every needle quiver.


temp gauge sender (single wire) is separate from ECT.

an overheated 4L is a dead engine usually, cracks the heads and blows the head gaskets

[bozzzz94]

Originally Posted by Gen

We just bought my wife a '95 Aerostar, 4.0, 4x4. Seems to run well. Has a noisy power steering pump. The problem we are having with it is the check engine light comes on whenever putting a load on it, mostly going up hills. I took it to someone and they tried pulling some codes off it but none came up. I notice there is a LOT of detonation while driving a low to medium RPM under load to get the light to come on. Would the decarbing procedure help out with this? Anyone else have this problem?

Thanks,
Gen

Detonation? I'd change out the plugs. That would eliminate a problem area there. Hi energy ignition cars will burn so hot that you will never know that you are running with a 1/4 inch gap instead of a .035 inch one. Run some sea foam through your block and then change out the oxygen sensor. You'd have a good start at it then.--Boz

[Gen]

Thanks for the input guys, here's an update. Replaced the spark plugs, wires, changed oil and filter, PCV valve, air filter and fuel filter. I get the impression its running smoother. The detonation is nearly gone going up a mile long hill. Just a hint of it as the rpm's got low. Check engine light came on just as I neared the top of the hill. About when the van was travelling is slowest with the engine loaded. Temp gauge never got more than 1/8" past the low line, ambient air temp was around 50-60 degrees this morning. I think my next step will be the decarbon treatment.

Thanks,
Gen

[Bear River]

Sounds to me like a MAF sensor is going south on you.