-- REVIVED POST -- ANSWER FOUND IN FORD TSB -- READ FURTHER DOWN IN THREAD FOR TSB DETAILS --

I've noticed recently that as summer approaches and the temperatures rise, my engine just doesn't have the performance that it does on cold days.

Last week, the high temperature rose into the mid-90s and my engine did not perform well. I would step on the gas but it seemed like there was no power and that the engine was working hard. I did a 0-60mph acceleration test and found that there seems to be RPM window in which the engine power seems to dip for a second.

The temperature has dropped back into the high 70s during the past two days, and the engine performance is much better.

Anyone else experiencing poorer performance on hot days? Any ideas?


------------------
2000 Ford Expedition Eddie Bauer 4x4
- 5.4L Triton V-8 (stock 260HP version)
- K&N FIPK Generation II
- Flowmaster 70 Series Muffler with Custom Dual-Exhaust
- Coil-Spring Suspension (No 4-Corner Load Level)
- 33x12.5R16.5 BFG All-Terrain T/A KO Tires
- 16.5"x9.75" Centerline Python Wheels (Style 63)

 

I fly for a living, and thus deal with aricraft performance versus Air temperature and density on a daily basis. When it is a higher altitude, hotter, and\or more humid out, this all affects density altitude. This is the altitude your truck (or airplane) thinks it is actually at if it were a standard day. If you are at a 3000 foot elevation, and it is a 90+ day, and quite humid, your density altitude will be about 6000 feet! That makes a big diference in performance, perhaps 30 to 40%, versus if you were close to Sea level on a cool afternoon.

The only way to increase performance is to make your engine breathe easier (exhaust, new air intake, like you already have). Or you can get a supercharger! Mind you, when it is high and hot, a blown engine will be affected as well, just not as much.

------------------
'97 F-150 4x4 SC SB 4.6L. Riding on Sport King 265/75R16 AT's. Add-a-Leafs and rear block lift, torsion lift. Side Bars. WMS Intake, TB spacer, and Superchip!

Wish list: 4.10 Gears, Hedman Hedders, 3" body lift, 33x12.5 MT's!!

 

You do get more HP out of an Engin on cold days because when air is cold it is more dense in terms of # of moleculed per cubic unit of measurement. The Combustion in the engin works on a molecule by molecule basis combinding the Hydrocarbon molecules with Oxygen. More dense air means more molecules can fit in the the fixed volume of your engin. I just installed a K&N air filter and notice a signifigant HP increase. more air means more O2 for the Fuel/Air Mixutre. This might not be the reason why you are experencing this phenomon. But It is sound physics and chemistry.

 

My engine does the same thing as yours. It runs good when it's 60 degrees but, when it gets to 80 degrees or hotter, it runs very poor and it uses alot more gasoline. I never had a vehicle that did this.

 

My Expy will do the same thing when it get hotter. It's getting into the upper 80's now but gnerally runs fine. Not as good a a crisp dry 50-60 but runs good.

When it get's up into the high 90's to low 100's and I'm sitting in traffic (where it chokes on lack or air circulation and extreme heat) I sometimes almost floor it just to get it to take off from a light. Once I get moving and get some air moving, it get's better. It's only done that a few times and in extreme heat and stand still traffic.

This is the first summer with the Superchip, Airaid and Gibson exhaust so we'll see what effect that has on it.

By the way, my first 0-60 times were in the mid 80's and humid and ran 8.22 and 8.34. Again another time in the evening about 80 and a little drier but with cooler evening aire, 8.22 and an 8.86 with a real bad start. For what it's worth....

(What the hell am I doing 0-60's in an Expedition for???)

------------------
2000 EDDIE BAUER EXPEDITION 4x2

• Estate Green
• 5.4 ltr
• 3:55 LS rear
• Superchip!
• Airaid FIPK
• Gibson S/S Swept Side Cat Back Exhaust
• Hellwig Rear Anti-Sway Bar
• Energy Suspension Polyurethane Front Anti-Sway Bar Bushings
• Edelbrock Performer IAS Shocks
• Mobil 1
• Xenon Super White Head and Driving Lights
• Tow Package
• Rear Load Leveling
• Moonroof
• Century Child Seat!

-->Follow Me...<--

 

I've noticed the same thing recently. On my way to work in the morning, the temp is around 75-80 and everything runs great. On my way home, the temp is at or above 100 and when I stomp on the gas, it doesn't have the "umph" it had in the morning. Figured it was air temp.

Is the radiator fan always on or does it come on when the engine hits a certain temp? I notice when it's hot outside and I'm in stop-n-go traffic, when I start moving, I hear this whooshing sound for 35-40 seconds then it goes away.

------------------
2001 F150 XLT Supercab 4x2 4.6L Auto 3.55LS Tow Package 2.2" 2 row radiator.

Mods:
Westin black nerf bars.

 

Thanks for all of your replies. It seems that I'm not alone with this problem.

The weird thing is that this is the second summer that my Expedition is going through, but the first summer with the K&N. Last summer, I didn't seem to have this problem with the stock air box.

I'm wondering if the K&N is letting too much hot air in, especially since the FIPK Generation II for the Fords doesn't have a "cold air baffle" that some of the other FIPKs. The FIPK for the Jeep Grand Cherokee's 5.2L comes with a cold air baffle that blocks off the exposed filter element from the rest of the engine compartment; therefore, hot air from the engine itself doesn't get near the filter.

I'm debating whether or not I should go ahead and make my own baffle to see if it helps.

It would be good if someone else has actually found a cure for this heat related performance problem.


------------------
2000 Ford Expedition Eddie Bauer 4x4
- 5.4L Triton V-8 (stock 260HP version)
- K&N FIPK Generation II
- Flowmaster 70 Series Muffler with Custom Dual-Exhaust
- Coil-Spring Suspension (No 4-Corner Load Level)
- 33x12.5R16.5 BFG All-Terrain T/A KO Tires
- 16.5"x9.75" Centerline Python Wheels (Style 63)

 

It's ECU programming. As the intake temps and engine temps rise, the computer pulls timing and adds fuel to prevent detonation. All Ford's do this to an extent. My Mustang feels likes it dragging an anchor on 100+ deg days with the A/C on. Can't say I've ever really noticed much of a difference with the truck though..

------------------
2000 F150 XLT 4x4 Short Bed. Amazon Green, 5.4L, SuperCab, ORP, Tow Package, Sliding Rear Window, Electronic Shift, Keyless Entry, LT265-70-17 Tires, Clarion Pro Audio, Herculiner Bedliner, Air Silencer Removed.

1994 SVT Mustang Cobra. #1032 of 6009. Black coupe with black leather int., 3.73 rear, Bassani Exhaust, Aluminum D/S, Bridgestone RE-71 255-45-ZR17

My Home Page

 

I'm reviving an old thread here because I just found my answer in a Ford TSB. There's two TSB numbers associated with this problem (15431 and 15630).

Here's what 15431 says:

15431 - LACK OF POWER IN HIGH AMBIENT TEMPERATURES
Some 1999-2002 Expedition and F-150 vehicles equipped with 5.4L 2V engine may exhibit a lack of power condition when the vehicle is operated in ambient temperatures above 100 degrees F, particularly during stop-and-go driving. By design, the PCM calibration retards the ignition timing to prevent detonation when the inlet air temperature (IAT) reaches temperatures above 140 degrees F. If the lack of power condition occurs only when the IAT is above 140 degrees F, do not replace parts in an attempt to service. Engineering has developed a new calibration which will be available early in the first quarter of 2002. If the condition exists in other temperature ranges, proceed with normal diagnostics.

Here's what 15630 says:
15630 - LACKS POWER IN HIGH TEMPERATURES - REPROGRAM PCM
Some 2000-2002 Expeditions equipped with a 5.4L 2V engine may exhibit a lack of power condition when operated in ambient temperatures above 100 degrees F, particularly during stop-and-go driving. This may be due to PCM calibration, which retards the ignition timing to prevent detonation when the inlet air temperature (IAT) reaches above 140 degrees F. A new calibration is available to service this condition. If the condition occurs only when the IAT is above 140 degrees F, reprogram the PCM to the latest level via the just-in-time process if your WDS communicates w/Fordstar. Also obtain calibrations on the Ford Professional Technician Society (PTS) website - select 'WDS' then 'PCM reprogramming' and click 'Instructions' for downloading. Calibrations are scheduled to be included in WDS release B17.10.

So, there you have it folks. The answer to your high temperature loss of power woes!

 

Thanks for this info. This is what I've been needing, but one question. The numbers you reference don't look like Ford TSB numbers. Don't they usually have dashes in them?

 

These were the numbers that the NHSTA listed as the TSB numbers. Also, I have a scan from the actual February 2002 update to the Ford Online Automotive Service Information System that lists the 15630 number. I don't know how to post a JPG image in my message though, so I can't attach the scan.

 

Okay, let's see if this works:

 

How do you access it?

 

Tenderpaw,

I don't know how to access the actual system, although it would be nice if we could. The scan that I posted is from a collection of downloads that I got from the NHSTA website.

I've also found one other problem that my local Ford dealership hasn't been able to diagnose (took the Expy in 3-4 times) that's listed on one of the TSBs. I guess I need to take a visit to them and show them the damn TSB myself.

 

RJ,

Does your Expidition have the insolation under the hood? Try removing it and see if you get any improvement.

JMC