'Check Engine'

[le33sw]

The 'check engine' light has come on my Explorer (1999, 4.0 OHV, 4WD, 110k miles).

It is running a bit rough. I also notice that it is rather hesitant to speed over 40mph - you can speed it, but it seems as if the engine is gasping for breath.

I put in a tankful of preimum petrol and a carburator/injector cleaner into the tank. No improvement.

Changed the plugs. No improvement. The garage that replaced the plugs said that the distributor wires to the plugs were fine.

The garages around here are asking for C$100 to do a diagnosis.

What could be the problem
Oxygen sensor?
Petrol pump?

 

[Shen2187]

Start it up, pop the hood. Listen for any "hissing" from the engine bay. If there is, tell me the general origin of the sound. If there is not, maybe someone else can help. I get the same symptoms when my engine will "cough" and blow some of the vacuum lines on the "octopus". (right rear by brake cylinder)

 

[FirstFordEver]

Sounds like the intake manifold gasket needs replaced.

 

[le33sw]

Started the engine and listened to the engine for a few mintues. I can't say I can hear any specific 'hissing'. What I did notice was that each engine 'rough' patch, the engine vibrates/shakes - runs smoothly, then shakes, runs smoothly, and so on.

To my uneducated mind it seems as if the engine is having trouble getting petrol - so it sort of coughs/shakes, and then gets petrol runs smoothly, and so on. Could the fuel filter be the culprit?

 

[Shen2187]

It could be as 'FirstFordEver' said, or a fuel delivery issue as you said. Both can have similar symptoms. It could also be a spark issue.

In your case, I would spend the $100 to have the diagnostic done.

Even if it is a small, easy problem to fix. You could easily spend much over $100 in new parts, trying to find the problem.

 

[CCr]

I had the same issue and spent around $300 to get it fixed only for it to start happening again when I was 2000 miles from home, I called and *****ed, they said bring it in and we'll hook it back up. they wanted to charge me more for the hook up so I told them to #### themselves. it happens more when it's cold out but isn't really an issue after the weather/engine is warm.

 

[ThePhoenix]

intake gaskets.....sounds like it

 

[Gator Jeff]

Before you spend ANYTHING, go to an AutoZone or similar McParts store and get your codes read. Most will do it for free, and of course only take it to one that does it for free. Once you have the codes, do a search here and you'll have a good idea of what you're looking at. My guess is that it might have the old P0171 and P0174 codes.

 

[le33sw]

I haven't found a place in Canada that does this sort of thing free. Everything seems to be expensive compared to the US.

Took it to the garage that replaced the spart plugs - the machine they used came up with 'Cylinder 4 malfunction'. They said that further analysis is needed and codes investigated, and wanted me to bring the vehicle tomorrow so that they can give me a quote on what exactly needs doing.

 

[le33sw]

Today, when I started the car (to take it to the garage) the light did not come on!
The engine isn't sounding very smooth.
Took it to the garage just in case - they said that they cannot find the fault without the actual fault being registered. However, they too agree that the engine does not sound perfect.
This is very, very annoying. Should I just keep on running. The gas mileage does not seem to be healthy either - admittedly, I have only run in town with constant stop start.

 

[le33sw]

It is back on... Grrrr

 

[ThePhoenix]

or maybe the fuel filter

 

[le33sw]

An update.

The fuel filter was changed - the old one was pretty dirty.

I did 700 miles over the w/e. At the beginning of the trip, the light was not on but it came back halfway across the trip. The drive involved highway type of traffic with fairly substantial climbs (and down of course!) in between. Overall it averaged about 22.5 mpg.

Any ideas what could be the source of trouble?

 

[BrooklynBay]

You could buy a scanner for the price that they want to charge for the diagnostic.

 

[le33sw]

Happy to report that the problem is now sorted.
The cylinder 4 plug (which was not replaced earlier, as it was 'stuck' according to the garage) had its head partially disintegrated. The misfire is now gone, engine running smoothly. Thanks everyone for their contributions.

 

[BrooklynBay]

Thanks for the update!