1974 F.5 engine redemption

[flx]

Hello,

I'm on the way of a renovation of my 1974 FJ40 (Euro spec). The target is to make my family Cruiser ready for another 30 years of good services but not to do a museum perfect piece.

While the body is being sanded my mechanic took the compressions on the engine and they are not as good as I would like to:

In PSI it gives you:
1: 94
2: 72
3: 92
4: 0
5: 81
6: 75

For n°4 my mech says the exhaust valve is leaky (but not sure how he knows).

When I drove it just before to start the renovation (including offroad) I had the feeling the engine was okay. A little rough because of the carb with all gaskets dry but with good stamina and accelerations. Actually the main issue driving at speed was the clutch slipping in case I was too heavy with the right foot. So I'm surprised to see a result that bad.


For information this engine never had a year without any usage but for a few years (before I took it back from my father and make it reliable again) was only been used a few times a year for very short distances.


What would you advise? Is-it some simple things to try to see the result?
And as I imagine I have to go the long route, what exactly will I have to do ? What parts will I need for the engine?



I don't think there is any use for that but as I'm here, a few photos from the engine:

Thanks,
Felix

 

[flx]

And not sure again if it can bring something to the question but the sound of the engine running recently:

Idle:


In load going up a trail:

 

[Pighead]

Best case scenario: adjust the valves and try the compression test again.
worser case: you've got carbon deposits preventing #4 valve(s) from closing. Next time you can get the engine running, try pouring a can of Sea-Foam down the carb (a little at a time, of course. Instructions are on the can or try searching "Sea_Foam treatment" on the forums).
Bad case: pull the head and take a look, maybe it's a burnt valve.
You don't say how many miles (or Km) are on the motor but it might be time for a routine valve job.

 

[flx]

Oh yes I forgot that, 130 000 km (80 000 miles), most of them the 15 first years of service of the vehicle.

Thanks!

 

[Pighead]

80 000 miles

I'm gonna guess carbon build-up or valve mal-adjustment then...

 

[lcwizard]

did it sit without use for long period before the compression test?

 

[Dizzy]

Nothing wrong with that motor from the videos. Actually, it sounds quite good. If it doesn't burn oil (check the spark plugs and exhaust), I'd check for good (slightly tight) valve lash, and rest on it.

 

[flx]

Thanks for the answers.

It's quite more positive that I was expecting.

Sea foam treatment looks like a good idea for that old engine but at this point the truck is being dismantled so not sure when we will have the occasion to try it. And particularly not sure if we will have the opportunity to try it before to have to chose to remove the head while the engine is out. (and not sure where I could get this product in France while in lockdown)

Valve adjustment we definitively have to check, next step was already to remove inspection panel and valve cover to see how it looks.
Before to do the compression test my mechanic was sure the result will be bad because in his opinion valves would have corrosion. I haven't seen it mentioned as a possibility so don't know if this is something that happened often and not sure how it's possible to solve it if it's the issue?
Truck definitively had periods of 6 months without use and slept outside for a long time.


Videos date from early November and since then I think the truck has been used a couple of time for very short distances and last run was end of February to go to the garage by itself, for its plastic surgery. So 45 days between last run and compression test.

 

[flx]

So... Now the engine is out.

For carbon deposit we checked though the intake/exhaust and it seems there is almost no carbon deposit, so probably not the issue.


I let you judge on this point with pictures from pistons 1 to 6:

(continued in 2nd post)

 

[flx]

Since then my mech also checked the valves adjustment and it was already ok. So for him now we should remove the head and check inside. If I remember correctly my last talk with him depending on what is needed he may be able to do it himself (I think if it's only cleaning the valves) or would need to send to a specialist (if valve seats need correction for example).
What do you think ?


Another independent point: My mech is suggesting to change the exhaust manifold (not sure what is the issue yet). If I had to, what are the manifold compatible? From schematics I think 2F exhaust manifold would not be a direct compatibility but any manifold from a 1F would? Is that correct?


Thanks !

 

[bikersmurf]

What elevation are you at? Sometimes elevation will lead to low numbers. The bigger concern would be the 0 psi and variance between cylinders. F motors will run on little compression if the pressure is even.

 

[flx]

The garage where the compression was done is at ~200m (650 feet ?).

In the idea of removing the head I was looking for head bolt thinking that would be easy...

Cylinder head for Toyota Land Cruiser FJ40LV - Auto parts

Cylinder head for Toyota Land Cruiser with FJ40LV

toyota-europe.epc-data.com

Cylinder head for Toyota Land Cruiser FJ40LV - Genuine parts

Cylinder head for Toyota Land Cruiser with FJ40LV

toyota-europe.epc-data.com

But I discover that the F.5 engine is the only one with 145mm bolts instead of 122

 

[Pighead]

Why do you need new head bolts?

 

[flx]

Well I guess it was standard habits to replace them while getting the head off, and at 4€ a piece easily available from Toyota for the other years I would have not hesitated much. Also my mech is more used to work on old Alpine and Renault Sport with small nervous engines which may be a different story.

But searching a few threads here it seems everyone re-use them on these engines so I'll hope they are not damaged in unmounting.

 

[Dizzy]

Once you look at the top of the bottom of the valve you will get a better sense of the deposits. That is where the worst of it will collect. Number one exhaust valve stem seal is failing (last photo).

Let's wait and see the condition of the valves and seats, and everything else up top.

Exhaust manifolds are harder to find than motors, and might cost you more too. Basically, any paired intake and exhaust manifold will work with any two-barrel carb, but the air cleaner, and accelerator linkage becomes an issue. I'd look into a heat-riser block-off plate, if the two manifolds are no longer mated. Headers are also an option.

Reuse the old head bolts; they are probably fine. Just make the threads clean in the block and on the bolts, and lubricate them to get proper torque.

 

[flx]

Thanks !

For the valve sterm seal does it needs replacement? Maybe I should already order the 6 as we are going to open the head and plan for replacement?

With the lockdown parts can be quite hard to source nowadays (Toyota France was completely closed until today but maybe I will succeed to get parts again this week). At least with the lockdown the work is flying to a speed never seen before !

(I think there are never too many pictures in a Cruiser thread )

 

[flx]

For the head bolts my mech fears that some will break. And I can understand him because up to now it has been a real slaughter of bolts to get to this point so he never expect to ne able to unscrew all bolts. And if et happens he is right we would be stuck (but I guess it's uncommon ?).

With the head comes the issues of the head gasket. The F.5 gasket is precise part-number 11115-60033, parts before and after are not compatible.
And obviously this one is NLA from Toyota.
All threads I have read here suggest to go for a quality Japanese aftermarket... The problem is that at this point I will need it soon and with the lockdown here everything is more complicated to deliver. And I have only found the Japanese aftermarket version is Australian et US shops... which will be very long to deliver even in normal times and not even sure it arrives by now...
The normal 4x4 parts supplier I use in Europe only list head gasket for <09/73 F and for 2F :/
The only source I found for F.5 head gasket in all Europe is this one in UK : Genuine AJUSA OEM Replacement Cylinder Head Gasket Seal [10087400] 8427769429880 | eBay
So... Does anyone know of another source in Europe that may have one ? Does anyone has an opinion on the quality of this Spanish manufacturer "AJUSA" ?


For the engine it still looks clean with what we can see now :

 

[flx]

Last one of this long serie, the manifold !


So, the issue is that a lot a material came of in removing the exhaust manifold and the gasket so the surface is not flat anymore and the new gasket can't compensate that much. So here the plan currently is to reassemble the 2 manifold (if I can get quickly the gasket that goes sin the middle...) and send it to be resurfaced.
For the heat-riser block-off plate you mentioned @Dizzy I think the issue would be to get one here. I think I would have to shop on US used market and have it shipped here. Not sure if it can be added a little later done the road to not block the global progress.

Thanks for reading all of that !

 

[Whiskerz]

With a large file you can clean up the mating surfaces on the exhaust manifold. Also in another 40 thread someone posted some nice aftermarket exhaust gaskets that seal very well.

 

[flx]

Ok thanks I'll search that!

When I say things go fast, head is already out. Haven't seen it but my mech judgement is seats are ok but valves need replacement.
This is the number 4 with 0 PSI:

Head bolts are fine so they are good to service again as everyone here said