Smoke (and Mirrors...)

[Hamish]

Hello from Australia

first post and first Landcruiser.

Have a 1995 (last major update model) FZJ80. Picked it up very cheap, and was expecting to spend some money on it. Its done 180,000 km (I think thats around 112 k miles) and I love it. Nevertheless its problems are:

1) It blows blue (yes blue) smoke on start-up for maybe 20 secs then she blows clear.
2) It blows blue smoke after idling for more than a minute (eg, at lights) then when you load the motor (increase oil pressure) she clears up.
3) Dipstick has dropped about 2 mm (no idea in inches) in 3000 km (2200 miles) of driving.
4) Did a dry compression test, and lowest reading was about 190psi. Highest 205 psi.

Highway driving (or driving at revs, or full noise), it blows clean, and isn't lacking power. Oil use seems to be around town (i.e., stopping at lights so the oil pressure drops). Over a 2000km (1200 mile) non-stop trip it used next to no oil. Various ideas thus far as to what the problem might be:

1) Valve stem seals. - Was, however, told that this couldn't be possible because of the enormous volume of oil in the head, and the motor would be blowing continual clouds of blue smoke...
2) PCV valve...
3) Oil rings - But why is the compression so high?...
4) Gunk and crud (oil) in various parts of the engine (thus requiring an oil additive etc etc)

Any ideas??

 

[RavenTai]

Welcome


Your problems list looks good except for the "enormous volume of oil in the head" comment, does not matter how much oil is in the head the leak rate is set by the size of the valve stem leak(s),

Go for the low hanging fruit first. Replace the PCV valve (OEM one is much better made than aftermarket) and make sure the two PCV lines are clear of obstructions.

A good test would be to cap the PCV valve and also its port in the intake. Then cap the other line at the throttle body to keep all crankcase gasses out of the intake stream. Add a length of hose to the port on the passenger side of the valve cover and route it under the 80 somewhere to provide a place for gasses to go overboard. (some oil vapor will come out of it) Run it this way for a few days and see if the smoke goes away. The length of hose should keep any dust from making its way upstream and into the engine.

Also check the passenger side PCV hose at the valve cover it is often cracked. Don’t think it would cause your problem but wile you are in the area take a look. It makes an air leak that bypasses air around the MAF sensor

 

[hefty_merv]

Firstly, good to see another Aussie on the forum...

Hamish, have you had a look at www.lcool.org

The also have a QLD group on there if you haven't already found out...

 

[landtank]

I'd also start at the pcv as well. Get a couple of ear sticks (Q-tip swabs) or what ever you aussies call them and swab the inside of the pcv tubes at their ends. This would give an idea of any oil getting by. I had an older 60 with major oil consumption and this helped me to identify the pcv.

Oil rings typically reside below the compression rings and act like a pump/squeegy to control the cylinder bore lubrication. On occation they will get gunked up and not squeegy properly and oil will travel past the compression rings and get burned off.

with your relatively low oil consumption I wouldn't get too crazy tracking down the blue smoke and just let the poor bastid behind you deal with it.

 

[cruiserdan]

12204-35040: PCV valve
90480-18001: PCV valve grommet
12261-66021: PCV hose
12262-66021: Crankcase vent hose

I'd start there.


Welcome......

 

[Hamish]

In my original post, I was just relaying what information I had come across in my search for the answer. I was going to start with the PCV this weekend (and all of the hoses). A couple of good ideas there. Thank you.


I was also wondering if valve stem seal often "let go" in these trucks (1FZ-FE), and if anybody else had replaced them before...

I'll check out the forums on the Australian Landruiser owners website.

 

[Rainy Day FZJ]

Blue smoke?

I had the same prob only smaller. I did the PVC and it helped, yet when I pulled the head to do the HG and valve seals I could tell that they were leaking on the valves and then burning off. Try a rubber glove open and wrapped over the oil fill on the valve cover, if there is excessive blow by or the PVC won't work, it will blow it up when reved.

 

[Hamish]

Rainy Day FZJ, After all that, did it solve the problem (valve seals etc)?

Like the idea of the glove. Could modify it to give an appropriate hand signal too... hehehe

 

[Rainy Day FZJ]

Valve seals

No I have not had the chance to see if it solved the light smoke on startup, yet my educated guess is that it will. There was light oil and deposits on the exhaust valves from the oil leaking down the stem. The glove works great, I would always do it before and after a PCV, especially on older subarus, they will leak like a flower sive when the pcv and hoses get plugged, also blow up the glove with blow-by.

 

[Hamish]

Noticed that there is a fair amount of gunk under the oil filler cap, so I am going to do a flush of the engine too. After a bit of digging around on the net I found this interesting pdf file about PCV valves (I wanted to know what was inside them and how they worked, not just what they did):

http://www.autoshop101.com/forms/h63.pdf

If there is gunk in my oil filler cap, the PCV is going to be choked too. Am looking forward to replacing all the parts in CDan's list on Saturday.

 

[LCphil]

Cotton buds is what they call them.

 

[Hamish]

PCV valve was clagged, hoses into the throttle body were disgusting. All replaced, including hoses. Also did an engine flush and oil change.

Has improved about 70%.

Thanks everyone for the advice so far...

 

[WestcoastLC80]

I’m sure this 15 year old thread is going to help me out. Fingers crossed