Lost Compression

slim · DUNDAS, ONT

Lost Compression

Chance · ENNISMORE, ONT

Hey Guys n' Gals

Been a busy summer! Hope ya'll have had a blast!

I have a problem with my 87 Ford F150 4x4 4 spd with the bull low.

I was driving home one day and the ol' boy just lost throttle, and started sputtering then lost oil pressure then it just died. My mechanic said I lost compression in 1 and 2 but that he liked me too much to fix it and told me to just put a bullet in it. I was wondering what people thought could have caused it, and where they would start to find/fix the problem. I would like to see if I can fix it myself and make it my busher/project.

I'm new at this sort of thing and thought i'd reach out for some wisdom and guidance to save me some trial and error. I know we have a number of talented people on here so lets hope they have some time to lend to this greenhorn.

Cheers!!

poncho62 · ADMINISTRATOR

Head gasket?

not as drunk as you thinkle peep I am · GTA, ONT

poncho62 wrote:
Head gasket?

thats what i was thinking.

with the engine cold remove the rad cap and take a look at the coolant (assuming that engine has a rad cap). if you see lots of bubbles then you are losing compression into the water jacket. could also be a cracked head or burnt valves or burnt pistons or a cracked block. all these parts can be assessed with the head off. id say that if you are willing to take a stab at it rather than just putting a bullet into it, pull the head and look for obvious signs of head gasket failure. if all looks good, then take a good look at the head/block/pistons.

not sure why it lost oil pressure tho. it would have lost oil pressure when the engine shut off but ........

if you can get it running long enough to check for bubbles in the coolant recheck the oil pressure.

is this a six or an eight cyl? i woulda thought an 8 would run well enough not to totally stall out on 6 cyls.

if its a good solid truck it just might be easier/cheaper to toss in a replacement engine but id check the head gasket/head/pistons first just to try to find the cause. replacing a head gasket yourself would be cheap enough if that is the cause.

Sniper · WATFORD, ONT

302 and 351 w engines had plastic covered cam gear teeth. The plastic will get brittle, split and fall into the pan making the chain extremely loose and gets everything out of time. Cam gets a way late holding valves open and they kiss the pistons, might be why 1 and 2 have no compression now. If you do fix it, pull the pan and clean it out real well, the plastic will break up into small enough pieces to make it past the pickup screen. It will get lodged in the pump relief and you loose oil pressure. Might have happened already, take the pump apart as well and clean it, and the screen, make sure to check the relief for plastic pieces.

-- Edited by Sniper on Wednesday 16th of October 2013 02:04:43 PM

not as drunk as you thinkle peep I am · GTA, ONT

Sniper wrote:
302 and 351 w engines had plastic covered cam gear teeth. The plastic will get brittle, split and fall into the pan making the chain extremely loose and gets everything out of time. Cam gets a way late holding valves open and they kiss the pistons, might be why 1 and 2 have no compression now. If you do fix it, pull the pan and clean it out real well, the plastic will break up into small enough pieces to make it past the pickup screen. It will get lodged in the pump relief and you loose oil pressure. Might have happened already, take the pump apart as well and clean it, and the screen, make sure to check the relief for plastic pieces.

-- Edited by Sniper on Wednesday 16th of October 2013 02:04:43 PM

that makes a lot more sense than a head gasket now that i think about it. also explains why the engine stalled. i would expect an 8cyl (still dont know if thats what he has) would still run on 6 cylinders ....... not run well but at least still run. that wouldnt be the case if the timing chain skipped.

either way i think the head still needs to be pulled .... a couple of valves or a used head from the wreckers would certainly be a cheap enough fix. i say pop the head (or heads) off and see whats going on. if the valves are bent then head for the timing chain and assess its condition. dont buy any parts till youve found all the damage.

good post sniper.

slim · DUNDAS, ONT

Hay if any of them plastic teeth are still pointy I could use a few.

shag766 · FOXBORO, ONT

if dave harvey still has a shop with towing in your area he is a pretty sharp cookie and honest. tell him rick shaughnessy gave you the name. after he gets off the floor from laughing he will be honest with ya.

yea i know, hard to believe smart and honest in the same sentence. good luck with getting ur done.

Cat in the Hat · BRANTFORD, ONT

Before you start tearing it apart

Id do a comprssion and leak down test

That will tell you if mr piston and ms valve kissed

Pull the valve covers and turn the motor over

Broken cam will not work the 1-2 cylinder valves

You get that deep you gotta pull it anyway

50-50 used motor or rebuild. All depends on your pockets

Could be major rebuild or $2000 long block

And skill level

Just sayin

-- Edited by Grumpsbodyworks on Tuesday 5th of November 2013 11:19:35 PM

Gazoo · BADEN, ONT

Can't be a head gasket, if it's cylinders #1 and #2 (unless it's an inline 6, 4x4). Those two cylinders are an opposite sides of the block on a V8, the odds of blowing both head gaskets are extremely slim.
Only #1 and #2 have low compression, is your mechanic 100% sure?
If it's a timing gear/chain issue, it would affect the compression in all the cylinders.
A broken cam is not likely either, this also would affect the compression on all the cylinders, unless it broke after #1 and #2, but then your compression would be good in these two cylinders.

I say pull the valve cover(s), and the spark plugs, get a piece of coat hanger (straightened out) at least 6" long and slide it in the spark plug hole. Turn the engine over by hand, this way you will be able to see, the rockers moving, and the coat hanger wire moving also. This will tell you that both the bottom and the top end are rotating (but not necessarily in sync).

The thing is, if you'd have a broken cam, you'd have no ignition spark also, as I don't think it the spark was crank driven sensor in '87.

You can dismiss all this rambling, if it's an inline 6, because then, I'd say it's a head gasket. If the compression checked good/reasonable in the other 4 cylinders, then it's probably worth the time and money to change the head gasket, but I personally would replace the timing chain and gears also.
But then again, I wouldn't waste any time and money on a 6 cylinder.
I'm no Ford expert here, but I believe Ford dropped that engine (in line 6) in the mid '90's.
A bit more/better info would be helpful, to try and resolve your issue.

-- Edited by Gazoo on Wednesday 6th of November 2013 03:34:29 AM

Fred Winterburn · RIPLEY, ONT

Chance wrote:
Hey Guys n' Gals
Been a busy summer! Hope ya'll have had a blast!

I have a problem with my 87 Ford F150 4x4 4 spd with the bull low.
I was driving home one day and the ol' boy just lost throttle, and started sputtering then lost oil pressure then it just died. My mechanic said I lost compression in 1 and 2 but that he liked me too much to fix it and told me to just put a bullet in it. I was wondering what people thought could have caused it, and where they would start to find/fix the problem. I would like to see if I can fix it myself and make it my busher/project.
I'm new at this sort of thing and thought i'd reach out for some wisdom and guidance to save me some trial and error. I know we have a number of talented people on here so lets hope they have some time to lend to this greenhorn.

Cheers!!

Just #1,#2 low on compression? How about a broken camshaft? Haven't heard of that happening on modern engines but it used to every now and again with a brittle casting. Fred

Fred Winterburn · RIPLEY, ONT

Fred Winterburn wrote:
Chance wrote:
Hey Guys n' Gals
Been a busy summer! Hope ya'll have had a blast!

I have a problem with my 87 Ford F150 4x4 4 spd with the bull low.
I was driving home one day and the ol' boy just lost throttle, and started sputtering then lost oil pressure then it just died. My mechanic said I lost compression in 1 and 2 but that he liked me too much to fix it and told me to just put a bullet in it. I was wondering what people thought could have caused it, and where they would start to find/fix the problem. I would like to see if I can fix it myself and make it my busher/project.
I'm new at this sort of thing and thought i'd reach out for some wisdom and guidance to save me some trial and error. I know we have a number of talented people on here so lets hope they have some time to lend to this greenhorn.

Cheers!!
Just #1,#2 low on compression? How about a broken camshaft? Haven't heard of that happening on modern engines but it used to every now and again with a brittle casting. Fred
Wait a second. One and two would be near the front of the engine so it couldn't be a broken camshaft. Fred

not as drunk as you thinkle peep I am · GTA, ONT

update:

as strange as this sounds it has been reported that pistons 1 and 2 have divorced and both have removed their rings.

Cat in the Hat · BRANTFORD, ONT

Update #2

Mr Cam Gear lost his teeth due to miss use

Ms Chain Jumped with surprise and threw Ms Valve of balance

Ms Valve unexpectedly then kissed Mr Piston

Mr Gasket exploded with anger and sent Ms Antifreeze after him

Mr Piston got hammered and lost his ring

Mr Piston got Ms Rod all bent out of shape

Ms Rod has lost her bearing. Mr Block threw her out

Stay tuned for another episode of..... " As the Small Block Turns"

hemi43 · ONTARIO

Looks like someone's been hanging around Rob Ford's crowd !!

parklane · St THOMAS, ONT

Gazoo, you sure about the cylinder numbers?? I know that a Chev is 1,3,5,7, & 2,4,6,8, but thinkf Fords are 1,2,3,4,&5,6,7,8, so it can still be #1 & #2 cyl.

Gazoo · BADEN, ONT

parklane wrote:
Gazoo, you sure about the cylinder numbers?? I know that a Chev is 1,3,5,7, & 2,4,6,8, but thinkf Fords are 1,2,3,4,&5,6,7,8, so it can still be #1 & #2 cyl.

No I didn't know about Ford's oddball, cylinder numbering system. You are absolutely correct.

Is the #1 cylinder the furthest forward in the blocks at least? Or just simply the right bank is #1, closest to the rad.

Kinda looks like Ford is the only manufacturer that uses that cylinder numbering logic.

not as drunk as you thinkle peep I am · GTA, ONT

dont forget not all ford v8s have the same firing order too. would be nice to hear what engine it was and what the issue ended up being.

Chance · ENNISMORE, ONT

sorry guys I've been too busy to get on this thing lately...it IS an Inline str8 6, 300 4x4 4spd.
my mechanic removed the plugs and did a proper compression test...and told me it would be around 2gs to fix. Since I got the truck for 700, I didn't think it was worth paying to fix. I put a new white oak/steel flat bed deck on it, and a few new replacement parts (rad, leaf spring mounts, brake lines, fuel lines, etc...) so it is still a nice old beater truck, and I wanted to try my hand at fixing it myself. I don't have any knowledge or experience, but I figured it wouldn't cost me much to putz on it and see if I cant get it running again. Even just for a plow truck, or whatever...so I was just wondering how some of you would go about trying to fix it....if you were gonna waste some time on an old Ford...heheh

cheers ya'll!

v8deuce · OAKVILLE, ONT

The 300 is a good old engine and for the life of me I can't see anything happening that quick to cause only two cylinders to loose compression except an head gasket.Did your mechanic tell you the compression e.g. 1&2 at 30 ibs and the rest at 125? My first step would be to try the simple things, remove valve cover crank over the engine while watching to see if all the valves are opening and closing this will tell you if you have any broken rocker arms or bent push rods or rounded off cam lobes,if everything looks good then check compression on #1 record that number then squirt some oil in the cylinder recheck compression if it's up a little or the same you have a burnt valve if it's up a lot the rings and or piston is bad.Try the same on #2 if that is the same then I would say that the head gasket is gone between #1 and #2. If that's the case you need to remove the head to check the gasket which is kind of what I expect because of the sudden miss you have described.If it is you can simply install a new gasket but I would spend a few bucks and check to see if the head is flat,any machine shop can do it or install a rebuilt head. Check around for prices. If you decide to remove the head there is lots of us on here that can walk you through the process. You have the easiest engine to work on so jump in with both feet,like you say you have nothing to loose and a lot to gain.

Randy

BARRIE, ONTARIO

I think the 6 uses a plastic toofed cam gear , and are a s o b to change . ie pressed onto cam . just put another motor in it ..77.

DaveM · ONTARIO

Tear it down!! We want answers!!!

427CARL · CLINTON, ONT

I have a problem with my 87 Ford F150 4x4 4 spd with the bull low.

I was wondering what people thought could have caused it

It all started in 1987 at a Ford plant Install chevy motor and have a great bush hog

RacerRick · TORONTO, ONT

If it is the 300, there is no timing chain (they are gear to gear), and it has seperate rod journals, so its not a rod or anything like that.

I would guess it is a head gasket, since it is not uncommon for them to blow. $2000 is way too much for a head gasket. At least pull the head and take a look - its just your time. If the gasket is blown, remove it and take a fine file across the head gasket surface on the block. You will probably find that the block is raised around the bolt holes and sunk between the cylinders. If it is, use the thick composition gasket like a felpro. If it is not, you can use a factory style steel shim gasket. Since you have the head off, get it plained flat, reinstall it. The gasket kit, machine work, and fluids should be under $200.

I scrapped a low milage 300 last year because I couldn't sell it for $100. Worst case scenario, if get another motor and throw it is. They are cheap.

Chance · ENNISMORE, ONT

Thx guys! I didn't have time to try anything before the snow fell, so now its just taking up space in my driveway..(just one spot I don't have to shovel!) However, I FINALLY broke down after being verbally assaulted by family and friends and bought a "new" truck for my growing family. I am now the proud owner of a 2012 Chevy Silverado 4 dr 4x4. Not what I thought I would be driving, nor spending that much on...but hey...its only money...and my kids safety is first. I have to admit, it is nice to have my first reliable vehicle. No more crossing my fingers every time I go to start...having heat And air! No exhaust fumes in the cab! I've have some offers to sell the old Ford, but nothing over 500. I would still like to fart around with it, and gain some experience as I would love to get more of that! (a start would be the most!)
When I get around to popping the hood again, I will start with what Randy and some others were saying , and check the head gasket. That was my original thought, and I usually trust the gut. And the gut is usually right.
How will I know if the gasket is gone? will it be obvious? or do I look for certain signs?
thx again for your input, and for not riding my ass for being a complete gear head rookie!!

54vicky · OAKVILLE, ONT

if when you get ready to tackle you have or can borrow a pressure gauge.remove the plugs on 1&2 cylinders.pressurize system you will see antifreeze coming out of plug holes may take a while depending how far pistons are down in hole.I have not tried with cold engine usually warm up to let thermostat open.I realize you cant start it to warm up.newer thermostats some times have a small bypass in them if yours does it may take a little longer to build pressure.as it bleeds down pump up again repeating till you see antifreeze seeping out plug holes.this will also work if head cracked.if you want to leave plugs in till you pressurize you can.