mileage got worse

[ARTURPOLAND]

Hi , another problem of my SOHC is growing gas mileage. It happened after i flushed the engine with oil change. It is a 97 model. What schould I check in order to limit my fule consumption. I also changed spark plugs to autolite platinium (maybe the plugs are of a bad type or gap is not proper). Or maybe the reason is somwhere else. I also had some valve tapping. changed oil to 15w40 and the problem gone, but one of our colegues said that I just masked the problem. Can something bad happen if I use 15w40 oil (engine has 220000 km on the counter).

Archie

 

[1996xlt]

If it gets below freezing I would think that an oil that is that thick would turn into molassass(sp?) and you could do more harm than good to the engine. My suggestion would be to switch back to the factory reccomendation of 5w30 maybe a synthetic if possible. I'm sure someone a little more versed will chime in.

 

[xFatcatx]

"Growing gas milage"? Your saying your getting worse gas milage lately right? I always use 5w30, 10w40 on older cars. What kind of milage are you getting? The best I have ever gotten with my 99 sport 4.0sohc was 17.5 miles per gallon and that was driving like grandma, nothing over 55 on the highway. I just filled up last night, and got 16.6 on this tank. Tank before that I drove like a mad man and got 13.7. Are you driving it harder, it will make a big difference. I have a locking gas cap now with the price of gas.

 

[ARTURPOLAND]

my fuel consumption is 14 mpg (city) and 19 mpg highway. It was a little better before I did those things (engine flush, plugs replacement). tel me if shot catalytic converter could be the culprit of my problems and how to check it ?

 

[JMan689]

Check your air filter. If the cat is clogged it might add to the problem but shouldn't cause a huge disturbance.

 

[FordTony]

I would never put anything thicker than 10w40 in a sohc motor..........anything more is gonna be to thick.............. If you have a ticking motor I suggest 10w40 oil with LUCAS oil treatment (about 4-4.5 quarts oil, and 1 quart LUCAS)

 

[FordJimbo]

I realize this thread is 13 years old but for archival purposes and to help others out in the future, I'll mention what I use and what I'm seeing. I recently acquired a high mileage 1998 Ford Explorer 4.0L SOHC 2wd with 202,000 miles. I've had it for four months and it's almost exclusively used as an inexpensive around-town commuter, dog park, grocery store, etc. vehicle. 75%-90% is stop/go sub 50mpg speeds. Very little highway. I drive very conservatively and rarely "get on" it. Sometimes I do punch it to the floor...

I recently have done oil change with semi-synthetic 5w30 (manufacturer recommended) [I normally would use full synthetic but this was a free local shop promotion.]. This week I did a tune up of replacing spark plugs (very worn and all were badly mis-gapped), wires (seemed to be fine but old), replaced the PCV which was not even connected to the drivers side exhaust manifold, and cleaned the mass air flow and throttle body. Replaced EGR.

I have been getting consistently ~17mpg, which I check at each fill up doing some quick math and using the trip odometer. And that was on unknown old oil, and in dire need of a tune up and with a mis-routed PCV and filthy throttle body and old EGR that failed emissions. I threw 5 codes and failed emissions, and needed a tune up.

This last fill up was 10.3 gallons and 178 miles, which gives me over 17mpg. Considering the work I just did, and having it idle for long periods many times, I'm very pleased with the mpgs. I expect it will get maybe even 18mpg next fillup due to the tune up.