NEED HELP!!! Vapor lock problems.

Reply Subscribe

Thread Tools

Search this Thread

Jan 13, 2008 | 09:51 PM

Mikes92F250

Thread Starter

New User

Joined: Jul 2004

Posts: 21

Likes: 0

NEED HELP!!! Vapor lock problems.

Help please, I have a 1992 F250 with a 5.8L. A few days ago I replaced the thermostat becaused I noticed the temp. go from cold to almost hot in a few seconds ( truck had been running about 10 minutes, blowing cold air with heat on). In the morning I plan to drill a hole in the new stat to allow the air to pass through. What would be the cause of the vapor lock? (bad hose, radiator bad, crack in the block)?? Any and all help would be great. thanks Mike

Jan 14, 2008 | 06:28 AM

projectSHO89

Hotshot

Joined: Jan 2004

Posts: 19,767

Likes: 1,082

From: St Louis

Vapor lock is a fuel system concern, you probably have an air pocket due to an incomplete fill.

Try the small air bleeder hole at the top of the thermostat to see if you can get any remaining air expelled from the system.

Steve

Jan 14, 2008 | 06:43 PM

Mikes92F250

Thread Starter

New User

Joined: Jul 2004

Posts: 21

Likes: 0

I did drill a small hole in the thermostat today, it does seem to be working so far (the temp gauge was consistant [I drove around for an hour or so] and did not overflow any to the ground). I had the system full, I though, then I checked it tonight after the truck cooled down and added another half gallon. May this will be it, fingers are crossed.
Thanks for the help, Mike

Jan 22, 2008 | 02:32 PM

Mikes92F250

Thread Starter

New User

Joined: Jul 2004

Posts: 21

Likes: 0

I think the head gasket is blown, I took the truck to the shop today. Hopefully my #8 cyclinder is not AFU too.

Jan 22, 2008 | 04:29 PM

Keepin It Real

Elder User

Joined: Dec 2006

Posts: 913

Likes: 0

Oil in the coolant? Coolant in the oil? Or maybe worse, can you see bubbling when you look into the coolant recovery tank? These are symptoms of bad HG. If not you may have just a sticking thermostat or coolant temp. sensor. Also does the rad. fan come on? Maybe bad fan motor or fan switch. You can check fan motor by turning on A/C (if you have A/C). Just some things to eliminate before pronouncing a bad HG.

Jan 22, 2008 | 11:14 PM

Mikes92F250

Thread Starter

New User

Joined: Jul 2004

Posts: 21

Likes: 0

When I had the radiator full there were still some bubbles when I had the cap off. (Had to add coolant every other day). The truck is in the shop right now I'll find out more tomorrow what's wrong.

Jan 23, 2008 | 12:42 AM

Madmike33

Elder User

Joined: Apr 2004

Posts: 748

Likes: 0

From: North US Border, Canada

I'm in the same boat, trying to figure out what's wrong on my 5.0L. Keep us posted.

Madmike33

Top 10 Fords at 2026 Carlisle Ford Nationals

Joe Kucinski

3 Best / 3 Worst Parts of Modern Ford Ownership

Brett Foote

10 Amazing Upgrades That Solve Common Ford Truck Owner Headaches

Pouria Savadkouei

Every 2026 Ford Engine Explained

Brett Foote

10 Ugly Ford Trucks That We Still Kinda Love

Joe Kucinski

10 Things Every Truck Owner NEEDS (2026 Edition)

Michael S. Palmer

Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath

Verdad Gallardo

Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer

Joe Kucinski

2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)

Brett Foote

Top 10 Ford Truck Tragedies

Joe Kucinski

Jan 23, 2008 | 10:17 AM

Madmike33

Elder User

Joined: Apr 2004

Posts: 748

Likes: 0

From: North US Border, Canada

Quote:

Originally Posted by 6lpowerstrokesrj

I have a brand new 3" thick aluminum rad, what you said might apply to someone else and is good info, but I have a lower head bolt leak that leads me to beleive I may be drawing in air from there maybe causing an air lock, I also suspect the thermostat, either way I need to fix the leak, and the thermostat is cheap to replace. As for air flow, I live in Canada so these days, it's not any reason for overheating.

Madmike33