TheLoudestSilence

The good news = I think i finally figured out whats wrong with my truck..

The bad news = A burnt valve.. I havent done any compression test or anything.. but the drivers side exhuast has a pretty bad suck back and spits gas.. unfornatly theres no way im going to be able to afford to fix this soon... im not sure how much its gonna cost but i know i gotta buy the valves and head gaskets and all and that alone is probably gonna be alot.. im happy and pissed right now...

on a happier note though i fixed my power steering leak with a bottle of lucas power steering stop leak.. that stuff works wonders.. i was surprised to see it work as good as it did.. im going to try the lucas oil stabilizer next.. hopefully i works as good as the PSSL

snookered

Can you get a junkyard head and put it on? We've got a few F150's here at pull-a-part.
(New Orleans area)

TheLoudestSilence

I really don want to put a JY head on it because i know with my luck ill be doing it again next month...

Now im not 100% sure its a burnt valve.. but i dont know if ive just tricked myself into thinking its not because i dont want to deal with it...

the drivers side pipe "hiccups" at idle... when it hiccups it sucks back air.. but it doesnt have a rythem to it.. I guess thats how youd put it.. it may hiccup once wait 3 seconds hiccup 3 times striaght wait 5 seconds hiccup again wait 2 seconds hiccup wait 5 hiccup twice.. you get the point.. the motor doesnt sound like it misses one beat though even while all this is going on.. it never over heats or anything lke that.. But sometimes on the highway when im doing like 80 or so and let off real fast it backfires.. it doesnt back fire any other time though.. just at highway speeds when i let off... The exhaust system on the truck is ****.. plain and simple it was peiced together and it looks like a four year old did the welding on it.. anyways based on all this what do you guys think???

snookered

Have you done a compression check?
What motor do you have?

A used head might be a good temporary fix.

bjafeman

Have you pulled the codes? How do you know it's sucking air?

I agree with snookered that without pulling codes, checking compression and maybe putting a vacuum gauge on it as well (can tell you if you've got a bad valve http://www.secondchancegarage.com/public/186.cfm) you're taking a wild guess. Not saying you don't know what you're talking about, just trying to save you the hassle of pulling off your head and finding it completely OK. Also, if it is the valve and you've just fixed the problem without addressing the cause...what if it comes back on the new head?

If you've got a crappy exhaust system in place, you may have a hot spot that could be igniting unburnt fuel from a plug that's cross firing b/c the wires aren't routed correctly (actually pretty common on these trucks). Yes, this is a wild *** guess that's more than likely nowhere near right, but without a few tests, why not call it the source of the problem as well?

In all seriousness, I had a bad exhaust system burn up a valve a few years ago, so you could be right, but it's worth testing first. Vacuum test can show you the bad valve while the engine is running. Start there. If it is a bad valve, the longer you let it linger, the longer it will mess stuff up. If you can't have any down time for the truck while you get the head rebuilt, pull one from a junker and bring it to the machine shop. This is one of the better ways of doing things b/c:
1) you get a practice run at removing the head on a junk yard truck. Snapped a bolt? Move to the next truck.....Reassembly is the reverse. You'll be ready for the job after pulling the head if you're not already.

2) you can still drive around while the work is being done. If you don't have the $$ yet, pull the head and drop it off at the shop anyway. Every time you feel that pop or hear the backfire it will be a little reminder to save some money.

Good luck.

TheLoudestSilence

I know its sucking air because i put a dollar bill at the end of te pipe and when it pops or hiccups what ever you call it it sucks the dollar toward the pipe instead of pushing it away...

Im going to work on getting a compression test done ASAP i just have to find the tool to do it.. im pretty sure my uncle has that kinda stuff..

TheLoudestSilence

Ok i took my truck over to my parents house today and me and my dad did some testing.. the compression test showed all 6 cyl to be consistent so no dead cylinders thank god.. my dad listened to the truck and messed around with it and he beleives the valves aren sealing good due to carbon build up.. he hinks e remedy for this is to run the motor get it out and then pour transmission fluid through it.. he says the Atf burns alot hotter and will clean the carbon with out hurting the motor..

The thing is my dads an old school mechanic.. hes use to working on 60s and 70s mustangs and trucks pretty much anything carburated with points and a distributer rather than EFI and all the computer sensors and stuff...

I tried talking im ino useing somthing like sea foam instead but being old school he doesnt think it works as good... so... Should i go let him try his transmission fluid theory or stop him? I know he knows alot about motors bu i don know if running ATF through my motor would ruin sensors and suff he doesnt know about

TheLoudestSilence

Well Im just gonna pull the o2 sensor off and try it.. why the hell not right? if it doesnt clean it then ill get some seafoam and try that..

bjafeman

Pulling the O2 is a good call if you're gonna run ATF through it. Try to stay clear of the throttle body opening if possible. Use a vacuum line from the manifold. The truck will likely survive with no harm done. The ATF trick used to work well on older cars, you never know, might do the trick. Sea foam after the ATF treatment. You should video tape the sea foam if you do it immediately after you run the atf through, it's gonna be a massive amount of smoke. Probably some kind of record.

TheLoudestSilence

Sounds fun lol..