Compression Issues (1 Viewer)

[Pfunkrasta]

My new-to-me 85 FJ 60/192K was brought into the shop and the mechanic is telling me compression ranges from low 80's to 110 and is recommending a engine rebuild vs seal replacement.

I'm trying to educate myself so not to get taken. I plan on getting a second opinion but questions should I be asking, what is a tell-tale for the need to rebuild and any other helpful hints would be great.

If I continued to run it, without a seal job or rebuild, what kind of damage would I do to the engine? Would a seafoam or Marvel oil additive help?

Anyone from Wilmington, NC??

Thanks

 

[gregnash]

If you continue to run it with low compression lots can happen as it depends on WHAT is causing the low compression.
Ask for a wet and dry compression test and what the numbers for both are and for each cylinder (get documentation of this). From there I would have a Leak Down test done to see if you can determine more information from that.

With that information you should be able to make a very good, informed decision as to what needs to be done (full rebuild vs. head gasket replacement say). Ultimately a full rebuild of the stock engine will run you anywhere from $3k to $5k depending on the shop and their charges. At only 192k on the engine you wonder what the PO did to it to make it have such low compression. Ultimately you COULD run it with the low compression you would just have little to no power going around town and could possibly detonate something along the way requiring a full rebuild.

Check the Clubhouse section for clubs in your area and see what good shops are nearby.

 

[SteveH]

Greg's advice is very solid. Get all the numbers from the shop and post them here, too.

what is a tell-tale for the need to rebuild and any other helpful hints would be great.

Does it smoke (more than perhaps a puff at startup)? Does it burn significant oil? Does it take a lot of cranking to start (as if it had low compression)? Are the plugs fouling badly? Is there a lot of blowby (pull the PCV or oil filler cap and see if a breeze/wind comes out when running). Is it gutless beyond normal FJ60 gutlessness? (This may require driving another FJ60 to determine this).

While you need a 2nd opinion, you should drive it a while and see how/if it meets your needs in its current condition. With any newly purchased vehicle (especially if you're not real familiar with 2F engines), I wouldn't be in a rush to do anything until you drive it some.

If a 'seal job' just means resealing the engine against oil leaks, then little damage will occur by driving it. If your intake/exh manifold gasket is leaking badly, then you shouldn't drive it extensively with a big vacuum leak. Find a GOOD Toyota shop (preferably Land Cruiser saavy) and see what they say about the power level and general condition.

 

[Output Shaft]

Have a "leakdown" test done to see if the leaking is past the piston rings or the valves. Google "engine leak down test". Maybe you just have leaky valves. If so, a head job is way cheaper and easier than a whole engine rebuild. 192k in the odo isn't very much for a 2F that's had normal oil changes and never majorly overheated.

My engine had low compression. All about 108 psi or so. I took the head in to get rebuilt and ALL the exhaust valves were leaking. After reinstalling the rebuilt head, the compression is now within spec.

 

[NeverGiveUpYota]

Yeah from everything I've read have what OS suggested done as well. It might not be as bad as it seems. Low compression is dependent on elevation too. If it's truly in the 80's then that's not great but 110 not so bad unless you are at a higher elevation.

 

[Pfunkrasta]

I'm at sea level. Coastal Carolina. No smoke, no knocking, decent idle, easy enough to turn over, seemingly good power and pick-up for someone who hasn't driven many/ doesn't seem sluggish. I brought it in because I just bought it and wanted someone to look it over, it needs a flywheel cover (anyone?), needs AC looked at and it does smell of gas/running rich. It was the smell of gas that had me most curious. I thought it may have been the carburetor.

The shop is telling me I have "blow through or blow by issues" (not super familiar mechanically just yet so terminology still not part of my lexicon).

I'm going to have a shop (blackstire.com) that a different 4x4 shop (lowrange4x4.com) recommended do a diagnostic. Will ask for compression and leakdown test. Will post when I get feedback.

 

[gregnash]

Compression is pretty easy and you can rent the tool from your local auto parts store like OReilly or Autozone. Get someone to help you turn over the engine and then write the numbers down yourself. If you want that is...
If you are not seeing smoke, idles fine, starts easy and has decent power then the first shop may be taking you for a ride.
The gas smell could also be coming from the rear. Take the back panel off where the filler neck is and see if you see any gas sloshing around in there. Also when you take the gas cap off do you hear/feel a large WHOOOOSH?

 

[roadstr6]

Here is one way to look at it. Rather than trying to eat an elephant in one bite, cut it up into pieces first. My point - Let's say you just re-do the head. You bolt it on and try it and and it turns out that you really need a full bottom end rebuild...at least you have a good head. You'd only be out a head gasket and labor for a head install. Rather than rebuild the bottom end, I'd probably take that good head and slap it on a replacement engine. You could always sell that head and recoup some cash if you end up not needing it.

I say this not knowing if you really need anything rebuilt at all. You might only need a valve adjustment and a tune up. Who knows? Don't lose hope though. You will get this ironed out. The road always starts out bumpy when you are messing around with old junk. You'll get the bugs out in time.

 

[Output Shaft]

There's an easy "compression test" you can do without a gauge. Just let out the clutch pretty fast while idling at a stop. If the engine lurches you forward without stalling, the compression is good enough. If you find you're stalling at slow idle take offs, (like on a four banger) the compression is too low.

 

[Pfunkrasta]

Can you elaborate/clarify? I know it's a proxy for an actual gauge test but I've driven new cars that if you let out the clutch quickly (in gear, i presume) without gas it will stall.

 

[Output Shaft]

2Fs pushing normal sized tires don't stall (when they're running right). In 26 years I don't think I ever stalled it once. And that included off road stuff. Only when my compression got real low did I notice I was stalling it at take off at low rpms.

 

[LAMBCRUSHER]

Did I miss where one of the guys suggested doing a valve adjustment and retesting? If so, then let me echo it. If not, let me offer it... do a valve lash and try again.

 

[micruz60]

The 2 F engine is tough, not dumb.
Do you have the Factory Service Manuals (fsm)?
Have you read the faq's?
Could you upload a video with sound of the engine running?
A well tuned 2F sounds like a sewing machine.
Keep it simple, no need to break it apart just yet...

 

[Pfunkrasta]

Thanks for everyone's insight. I took it to another shop (Vandalay Motors, Wilmington. Named after Vandalay Industries from Seinfeld, had a pic of The Kramer in their office) based on rolling up next to a guy in a 86 fj60 at the stop light and asking about his mechanic. Mechanoc told me, just by driving and listening that I didn't have a compression issue and that the gas smell seemed to be coming from a cracked intake into the carburetor and my oil leak was most likely a simple seal by the drainage nut. Major engine rebuild crisis averted. And I won't be going back to the other shop.

 

[HemiAlex]

Have a "leakdown" test done to see if the leaking is past the piston rings or the valves. Google "engine leak down test". Maybe you just have leaky valves. If so, a head job is way cheaper and easier than a whole engine rebuild. 192k in the odo isn't very much for a 2F that's had normal oil changes and never majorly overheated.

My engine had low compression. All about 108 psi or so. I took the head in to get rebuilt and ALL the exhaust valves were leaking. After reinstalling the rebuilt head, the compression is now within spec.

Exactly what happened to mine.

A head refresh woke it up completely.

 

[gregnash]

Thanks for everyone's insight. I took it to another shop (Vandalay Motors, Wilmington. Named after Vandalay Industries from Seinfeld, had a pic of The Kramer in their office) based on rolling up next to a guy in a 86 fj60 at the stop light and asking about his mechanic. Mechanoc told me, just by driving and listening that I didn't have a compression issue and that the gas smell seemed to be coming from a cracked intake into the carburetor and my oil leak was most likely a simple seal by the drainage nut. Major engine rebuild crisis averted. And I won't be going back to the other shop.

I would still do the compression test just for piece of mind to see where you are at. Do a valve adjustment to make sure everything is within spec and then go from there. Amazingly there are guys that have had some issues and simply adjusting the valves has cured a lot of things... Do the valve adjustment COLD as it makes things MUCH easier on you, when doing you add .002 to each the intake and exhaust numbers in the manual. Do some looking on this as I cant remember exactly what the numbers are.

 

[Vicente Madrid]

I've been having very similar problems. I got mine (83, FJ60 @ 160XXX miles) a couple years ago, it sat two years prior. After dealing with fuel system and carburetor issues. I got a Webber carb., A DUI hei ignition and mostly de-smogged. It ran like a champ, so much power!

Then, one day it just started running terrible. Rough idle, easy to stall on take offs and severe power loss up hills (more so than normal). The compression was reading similar.

He recommended getting the head rebuilt or replaced. I have been hesitant just because of how it all of a sudden, one day; got bad. I'm thinking of just getting it rebuilt but, it'd be great to save a couple hundred$$$$.

P.S. I'm new to this, should I have just started a new post?

 

[HemiAlex]

I'd check the valves first.

 

[SteveH]

Then, one day it just started running terrible. Rough idle, easy to stall on take offs and severe power loss up hills (more so than normal). The compression was reading similar.

Look at tuneup stuff first - did your timing slip - that sort of thing. It's unlikely the head or engine suddenly developed major internal problems without warning. Post your actual compression numbers here, before you pull the trigger on a rebuild.

 

[the gimpey one]

Make sure you run non ethanol gas as well.