New 5.0L built, low compression and horrible MPG

[1997XLTRollover]

Ok, 90s Ford odometers strip gears often. Known and common problem for Ford. As for your cam...

To improve emissions and get past smog car companies usually retard their cams and cam drive together. You put a new non emissions chain and sprockets right? Wellllll maybe the cam alignment is off set for a factory build and with the new equipment its way off base... I have read a lot about being careful with stock components due to having to meet emissions in older V8's when building them up...

Just a thought from a learning amateur

I just bought a replacement timing set for a stock engine. I have no idea what it is. I doubt that would be the case. How can aftermarket companies make all these stock replacement components and have timing off from factory stock?

 

[Joe in NY]

There are replacement emission components and off road replacement non emissions components. Each are made made different..

 

[1997XLTRollover]

There are replacement emission components and off road replacement non emissions components. Each are made made different..

Oh like something for California emissions you mean? This could be the issue because my 99 HAULS, and I mean HAULS ass. My 99 has stock manifolds and my 96 has TM headers with a 306 and the 99 would kick the **** out my my 96 at the drag strip no doubt in my mind. The 96 runs ok it just seems flat and torqueless.

 

[1997XLTRollover]

There are replacement emission components and off road replacement non emissions components. Each are made made different..

Check out post 22. Does anything in those 2 pics look off to you? Wrong gears or anything?

 

[1997XLTRollover]

Oh boy.

http://www.summitracing.com/parts/c...cwh_9hwFBVQ8DMO4Z42vCsuEvFDjNR0BQBBoCOLzw_wcB

Looks like they have 3 different keyways on the crank gear on this set. I'm not going to lie. I ASSumed those were all the same and didn't even think of any reason why they were on there if mine has 3 keyways. This is what I get for rushing to have a vehicle to drive for winter and keep the Mustang out of the salt.

I don't recall if mine had any adjustment or not or if it was just one set keyway.


Much like myself, I'm betting my engine is 4 degrees retarded.

 

[Dono]

hahaha.
Lets hope that you motor's cam is retarded, I highly doubt you are.

I really hope that this is the case, and since everything is still pretty fresh you should be able to get the front apart with the motor in the truck without too much swearing. Getting that harmonic balancer off is going to be the biggest challenge. I'm sure with the rad out, you will be fine.
Weekend project, here we come!

 

[1997XLTRollover]

Well I talked to the guys at Grumpy's Performance that I got the stuff from and it looks like I had kit Enginetech "TS163A" which based on looking online only has 1 set timing mark.

Has anyone used this kit before? Could this kit be the problem? (it only having 1 mark would explain why I didn't question anything).

 

[1997XLTRollover]

Bumping this up guys. I finally got my 96 back on the road and it looks like the "new" o2's didn't do anything nor did fixing my odometer. Thing is still getting 9-10 mpg. I feel like I should be getting 17-20 being how fresh this truck is.

This is really starting to get old. Does anyone know if that timing set I have is an issue? The truck seems to run ok but I just can't believe I could be getting this bad of mileage and not see an issue.

 

[beach]

Bad doesn't even begin to describe what this guy put me through. Destroyed my 5.4L Block (dropped it and cracked it), smashed numbers on my $2200 Trickflow heads right on the valve cover surface so they'll now leak, put followers in backwards on my heads (yes this means he put the followers on and THEN torqued the cam down), assembled 2 RH heads instead of a L and R, lost one of my new valve retainers for my 306 and used a random one not meant for my spring, which in turn totally screwed up my spring height on that valve (he thought this was ok), told me to order standard pistons because the block was good at std bore, I got the block back and it was a 20 over 5.4 (I ordered custom forged pistons and waited months for them) so then had to buy a brand new GT500 block that was standard bore for almost 1000 bucks because I couldn't return my custom pistons, he threw my new $1500 set of Manley pistons and rods in a box (no padding) and they got all dented and scratched up, then also even though I gave him the Manley instructions, during balance he ground off material from the rod cap which Manley specifically says not to do ETC ETC ETC.

The guy was a real piece of work and denied everything. Claimed that retainer is what came with my kit (that's BS but regardless the spring height was completely wrong, why would you install it if it was the wrong retainer and not just call me?), he claimed my block was cracked when I dropped it off even though I had pictures of the serial number and the spot he cracked before I dropped it off showing it was perfect. He wouldn't give me anything, he was a real jerkoff pardon my language.

For anyone wondering this is Sigafoos Machine in Easton PA. Don't go there. Guy used to have a good reputation but has went severely downhill and is a 60 some odd year old baby. Wouldn't even talk to me, he stormed off and told me to get the hell out of his shop. He literally threw an engine block into the back of my truck and dented the side of the bed and almost crushed my heads in the process then stormed off.

Geeze, you have way more patience then me, I would have cracked him in the face 60yrs old or not. Wtf.....

Honestly have no clue, seems everyone had suggested what could be checked and you've checked everything. Are sure the smell isn't oil drip onto the cat? I had a similar issue and smell and couldn't figure out, was definitely from the passenger side. Ended up my PCV was bad and oil was coming out of it slowly. Except it was so slow that any drive and would be burned off and couldn't track it. After it sat for a bit when I started working on it, it dripped enough down the passenger rear of the block right onto the cat and I saw it smoking and the rubber smell when I first started it up. Put new PCV in, cleaned the oil from the block and bellhousing and cat, no problem or evidence of leak since and no more burnt smell. Also thought it was the valve gasket as the leak can look the same.

 

[1997XLTRollover]

It could be. I know my front main is leaking a bit, but my PCV valve was moving around just fine before I put the engine back in. I cleaned it out too before I put it all back together. It could be leaking back there but who knows. I almost was thinking maybe my exhaust hangers are burning for some reason. I feel like I smell it coming from my passenger side rear wheel well the most. Tires are not warm though so it has to be something else.

Could my cats be clogged and overheating my exhaust and burning the hangers? Then obviously killing MPG because of the clog? I pulled the y pipe down and looked inside best I could and all looked ok. No rattling of any kind either.

I'm also going to pull the serp belt off and make sure a pulley isn't seizing up loading the engine down. Even though I replaced all the bearings for the hell of it while it was apart.

 

[beach]

It could be. I know my front main is leaking a bit, but my PCV valve was moving around just fine before I put the engine back in. I cleaned it out too before I put it all back together. It could be leaking back there but who knows. I almost was thinking maybe my exhaust hangers are burning for some reason. I feel like I smell it coming from my passenger side rear wheel well the most. Tires are not warm though so it has to be something else.

Could my cats be clogged and overheating my exhaust and burning the hangers? Then obviously killing MPG because of the clog? I pulled the y pipe down and looked inside best I could and all looked ok. No rattling of any kind either.

I'm also going to pull the serp belt off and make sure a pulley isn't seizing up loading the engine down. Even though I replaced all the bearings for the hell of it while it was apart.

Look at your cat and rear block and bellhousing, more then likely its oil thats very very slowly dripping onto the cat. You can spray brake cleaner around the housing and rear of block , clean/wipe up. Then check it after a few days or week, if you see any oil marks anywhere you know there's a leak.

 

[1997XLTRollover]

Look at your cat and rear block and bellhousing, more then likely its oil thats very very slowly dripping onto the cat. You can spray brake cleaner around the housing and rear of block , clean/wipe up. Then check it after a few days or week, if you see any oil marks anywhere you know there's a leak.

I hate when brand new engines leak... lol. New everything and it leaks and gets horrible fuel mileage.

 

[Bobmbx]

I didn't read through the whole thread, but have you had this thing dyno'd yet?

I'm wondering if your TQ isn't transferring the all the power to the drivetrain. Could the impellers be "slipping" or cavitating?

 

[1997XLTRollover]

I didn't read through the whole thread, but have you had this thing dyno'd yet?

I'm wondering if your TQ isn't transferring the all the power to the drivetrain. Could the impellers be "slipping" or cavitating?

No I have not. That's pretty expensive especially for an AWD dyno. I just bought a laser heat gun and I'm going to test to see if one cat is getting hotter than the other.

I may run another couple thousand miles and check my plugs again, but the engine seems to be running just fine. No stumbling, pulls all the way to redline, idles smooth seems to have ok power (although maybe timing is a hair off somehow and causing bad MPG and a slight power loss). I haven't been able to do a leak down test because I can't find a frickin leak down tester that will fit in the 302 heads. But compression is very even almost dead on 135 on all cylinders. I know some guys say that's low but my 99 came up with 135-140 on all 8 too with 160k miles and it got 17-20 mpg. So regardless if that's low or not my 99 pulled 17 so my 96 should too.

What kills me is the thing has a MAJOR issue. To get only 13 mpg straight highway and 9-10 mixed is so far off what it should be getting I can't believe I don't see anything obvious, nor can I believe it runs as well as it does. I even went as far as having someone drive a leg of a trip and clock miles to make sure my odometer was reading right, and it is.

I don't smell any gas leaking and have no CE light. I was getting to the point where I was thinking the gas was leaking or something because everything just seems fine but I don't smell anything at all.

 

[Bobmbx]

Have you had any emission tests done? If you're running rich, it should show at the tail pipe.

But, a failed or failing TC can really screw with your fuel economy.

 

[1997XLTRollover]

No the truck isn't due until August next year. Far as the torque converter I don't think it's bad, it seems to lock up and not slip to me. Unless you think I wouldn't even feel it. I'll be pissed because I just had the damn engine out of this thing.

I'm wondering if my maf is bad. I did clean it but maybe it's reading wrong? I'll have to check the plugs again, that's the weird thing is based on looking at the plugs after 1500 miles they look just fine indicating the engine should be running well too. But maybe they just need some more miles on them. I'm going ot play with it some this weekend and see if I find anything.

 

[koda2000]

find the reason for your low compression and you'll have your problem. to me, that can only be piston ring or valve related.

 

[1997XLTRollover]

find the reason for your low compression and you'll have your problem. to me, that can only be piston ring or valve related.

I don't believe I have low compression. It's probably still breaking in but my 99 had the same compression my 96 does now and got almost twice the fuel mileage. How could that be possible if my compression in my 96 was low yet my 99 had the same compression?

I suppose I need to do a leak down test. But does anyone know of a tester that will fit? I've got 2 and neither will fit down the plug well.

 

[1997XLTRollover]

Well I managed to do some work tonight. Pulled my serp belt, all pullies spin free. Although I did find out that my ac compressor is a little squeaky, that could account for my bird I have under my hood. Might just get a shorter belt and bypass that, but for now I'm leaving it alone since there's nothing wrong with the bearing.

I cleaned the rusted grounds on my coil packs and cleaned the bracket off too. I can't say I noticed a change, which is about what I expected. But they did look pretty rusted and I never cleaned the paint off my bracket between the pack and bracket, so I'm sure it's grounded better now.

I also read the codes just for the hell of it and low and behold I actually did have one stored. EVAP leak. Is it possible I have an EVAP leak somewhere that's causing a vacuum leak and killing my fuel mileage? I would think I'd need a pretty big leak to cause a 5-7 mpg drop and if it were that bad I would also think the truck would run horrible. Thoughts on this?

 

[1997XLTRollover]

Have you had any emission tests done? If you're running rich, it should show at the tail pipe.

But, a failed or failing TC can really screw with your fuel economy.

Do our trucks have a transmission fluid temperature sensor? Maybe it's never commanding full lock up and slipping the converter? Although I really don't feel any slipping.

Maybe also one of the ECT sensors? I have an ultra gauge and the engine temp says it's perfect at 192, but I'm not sure if that's the temperature the computer is seeing, or if there are more than 1 ECT sensors on our trucks and there's a different one that the ultra gauge isn't seeing.