Paging Ford Focus People and All Parking Lot Mechanics!

"liquid_popcorn" (liquid-popcorn)
12/27/2013 at 09:03 • Filed to: parking lot mechanic, ford focus, pos

This is the car my sister in law drives. 189k miles. Recent oil change (castrol high mileage + pure one filter), new Conti tires, new front pads as of Christmas morning.

Here's the thing: she asked me to test drive it after doing the brakes, as she said it was acting up. I drove it, noticed small but abrupt spikes and drops in revs when under load, and some hesitation in all gears. It sounds asthmatic and power delivery is not consistent.

What do you think is broken? The dealership that originally sold it new to her father quoted $115 an hour to look it over, so I'm hoping to narrow down causes and maybe troubleshoot it myself before we have to resort to that.

DISCUSSION (33)

Nibbles > liquid_popcorn
12/27/2013 at 09:05

Vacuum leak?

Sounds like vacuum leak

liquid_popcorn > Nibbles
12/27/2013 at 09:06

How do I check for that? Never had to deal with it before.

Nibby > liquid_popcorn
12/27/2013 at 09:07

Vacuum leak!

505Turbeaux > liquid_popcorn
12/27/2013 at 09:07

check yo vacuum lines. Move them around a bit, especially near the tie in to the brake booster. If the check engine light is on check for a RPM/crank sensor code. If no CEL and the vac lines check out, listen for any erratic noise out of the fuel tank. The fuel pumps suck on these, as well as the emergency fuel pump cutoff that disables when the airbags blow. Also the coil packs overheat on these. Top 4 things I would check

Arch Duke Maxyenko, Shit Talk Extraordinaire > liquid_popcorn
12/27/2013 at 09:08

Look at all of the vacuum lines under the hood. If you can, try to hear or feel for the leak. If you still can't find it, get it smoke tested.

Lazzris > liquid_popcorn
12/27/2013 at 09:10

If its a sohc I had the vacuum line on the head which is a short 90 go bad a give a slight sputter. Also if its a little worse then that my spark box had a crack on the bottom that would give a sputter at first start up until it got real bad that it dropped spark on one cylinder 500 miles from home.

liquid_popcorn > Arch Duke Maxyenko, Shit Talk Extraordinaire
12/27/2013 at 09:10

Awesome; thanks!

RobertBreedlove > liquid_popcorn
12/27/2013 at 09:11

Change the spark plugs and wires, check the grounding wires to the engine and their connections, check the fuel pressure/flow at the injectors, you could have failing/clogged injectors if the pressure/flow is good, check the timing belt and timing. Jack up the rear end and drive a new car under it.

Nibbles > liquid_popcorn
12/27/2013 at 09:11

Locate the vacuum lines (little black rubber hoses, generally starting at the intake manifold and going elsewhere). First perform a visual inspection. Treat 'em like you would any other rubber product: cracks, holes, cuts, anything other than nice black rubber, should be replaced. This stuff is cheap; like .50/ft last time I bought some. Go crazy

If they look good or decent at least, and you can't find any real visual issues, get some starter fluid. Fire the car up and VERY CAUTIOUSLY - you are holding a flammable liquid of course - spray some starter fluid at the vacuum hose junctions. If it revs up, you have found an air leak

You can also check the couplers at the MAF sensor (between the air box and intake manifold) and intake manifold. Unmetered air entering the engine is one of the major causes of your symptoms, and sometimes an incorrectly installed or cut junction boot can cause this as well. Again, starter fluid helps BUT BE CAUTIOUS

Nibbles > Arch Duke Maxyenko, Shit Talk Extraordinaire
12/27/2013 at 09:12

Smoke test. Why didn't I think of that. Much better (and safer) than using starting fluid lol

505Turbeaux > liquid_popcorn
12/27/2013 at 09:12

nah no sense in smoke testing, crack a propane torch open and trace all the lines under the hood with it. If you hear the engine note change, there is your leak

Arch Duke Maxyenko, Shit Talk Extraordinaire > liquid_popcorn
12/27/2013 at 09:12

I've had to deal with many.

liquid_popcorn > RobertBreedlove
12/27/2013 at 09:15

How do I check fuel pressure/flow? Never done it before.

liquid_popcorn > Lazzris
12/27/2013 at 09:17

I believe it is a SOHC; I'll verify that when I'm with the vehicle again this weekend sometime.

André - Volvo4Life > liquid_popcorn
12/27/2013 at 09:37

Another vote for vacuum leak, is the CEL on?

thereisnospork > Arch Duke Maxyenko, Shit Talk Extraordinaire
12/27/2013 at 09:55

For a ghetto smoke test grab a cheap cigar (or two). A swisher or whatever they use to wrap blunts by you should do fine. With the car off, light 'er up and then pop a vacuum hose and exhale smoke into the intake meanifold. Repeat a few times then cover the hose you unplugged with your thumb and look to see where smoke is escaping - that's your vacuum leak.

Note that some smoke may slip past the throttle body, which is normal. Also you may need/want to test the system in pieces, eg pop a line leading to the intake manifold, then use a line that leads to a vacuum reservoir (if any) etc.

Its not perfect but when it works it is awesome.

johnr240z > liquid_popcorn
12/27/2013 at 10:00

Check vacuum leak like everyone else said. I have a Focus SVT and had similar problems. Check the breather tube from the airbox to the valve cover as well. That hose came disconnected on mine and I had hesitation problems.

Also change spark plugs, wires while you're at it if you haven't recently. It's super easy to do and might make a big difference.

Lazzris > liquid_popcorn
12/27/2013 at 10:04

The sohc is also Known for bad heads can't remember exactly what goes wrong with them.

liquid_popcorn > André - Volvo4Life
12/27/2013 at 10:16

It wasn't when I test drove it Christmas day, but I'll be checking it out tomorrow evening after work, so I'll update then.

liquid_popcorn > johnr240z
12/27/2013 at 10:17

Ah, good to know; thanks!

I'll probably do the plugs and wires while I have the car; I doubt they've been done recently anyway.

André - Volvo4Life > liquid_popcorn
12/27/2013 at 10:18

My wife had a 2003 that had a Vacuum leak, it showed all the same symptoms as yours. Mechanic diagnosed it in .03 seconds.

JEM > liquid_popcorn
12/27/2013 at 10:35

2nd the spark plug wires. Never had a Focus but I've had this happen with 1 or 2 other cars and sure enough, spark plug wires. If they haven't been changed in like 100,000 miles that could easily be it right there.

liquid_popcorn > André - Volvo4Life
12/27/2013 at 10:42

Sweet! I hope that'll solve it; cheap fixes are nice.

liquid_popcorn > JEM
12/27/2013 at 10:43

Almost definitely haven't been changed, haha.

johnr240z > liquid_popcorn
12/27/2013 at 10:52

Ooh yeah. If you don't know when they were last done definitely do them. It's cheap and it could fix your problem. Mine went bad on my Focus around 100k. I also replaced the ignition coil with an MSD performance one since it's easy to get to but you shouldn't have to do that.

liquid_popcorn > johnr240z
12/27/2013 at 10:59

Good to know. I may do the coil as well while I have the car - I'll have to ask her what her budget is.

N60sdm > Lazzris
12/27/2013 at 11:00

I second this. Have heard about this as well.

johnr240z > Lazzris
12/27/2013 at 11:37

I heard it was bad valve seats on the CVH/SPI SOHC engine. They can drop a valve seat even if the engine has been well maintained. Usually happens after about 100-120k miles.

Lazzris > johnr240z
12/27/2013 at 11:43

Yup a little over 150 for mine after I sold it to a friend. He had it fixed for $1000 and is still driving it.

The WB > liquid_popcorn
12/27/2013 at 13:02

Vacuum leak does sound like a possible culprit like the others say.

When was the last time the fuel filter was changed?

liquid_popcorn > The WB
12/28/2013 at 09:15

No idea, honestly. I'll be finding out more tonight when I get a look at it.

The WB > liquid_popcorn
12/29/2013 at 13:32

Any luck?

liquid_popcorn > The WB
12/29/2013 at 16:32

Somewhat; CEL code was for misfire cylinder 4. replaced plugs and wires (they were all original!), issue isn't completely resolved. She had to leave, but I'll be checking the ignition coil tomorrow, then proceeding from there. If I can get her to pay for it, I'll probably change the fuel filter as well. She said it had been done "recently," but that's what she said about the plugs as well, haha. I'll update my main post when I've had another look.