Tapping sounds, white smoke but oil pressure good??? Help!!

[louise]

Our diesel patrol 2.8L (1999) GU was making tapping sounds while driving, which increased as the rev's went up. A day later started it blowing a bit of white smoke. The oil pressure is good, there are no oil leaks. First mechanic said he the 'bottom end' was Ok, then looked at the top and couldnt find anything (not sure how well he looked at it though, as he didn't spend long on it). We took it to the next mechanic, he didn't look at it, just said you will need a new motor, as it would cost $1000 to open it, and $10,000 to get a new engine. Third mechanic drove it, and said needs new engine but doesn't know where the problem is. Does anyone have any advice, as I am confused as to why the oil pressure is good and the car still drives - why would I need a new engine? Is there something we could check first, as I love the car but dont have that sort of money to spend in one hit.

[Bloodyaussie]

What area are you in as there are people on here who can recommend good 4wd mechanics to try and get answers.

[AB]

Hi Lou, hopefully some others can have some input but the below might explain some things.

Stolen from this post (http://www.nissanpatrol.com.au/forums/showthread.php?12450-Why-Diesels-Smoke)


White smoke occurs when raw diesel comes through the exhaust completely intact and unburned. Some causes of this include…
Faulty or damaged injectors
Incorrect injection timing (could be a worn timing gear or damaged crankshaft keyway).
Low cylinder compression (eg caused by leaking or broken valves, piston ring sticking, cylinder and/or ring wear, or cylinder glaze)
When white smoke occurs at cold start, and then disappears as the engine warms up, the most common causes are fouling deposits around piston rings and/or cylinder glazing. Use of our Flushing Oil Concentrate and FTC Decarbonizer address these respective problems.

Water entering combustion spaces will also create white smoke. Faulty head gaskets and cracked cylinder heads or blocks are a common cause of water entry, and are often to blame. Unfortunately, expensive mechanical repair is the only proper solution here.

[Alitis007]

Blowing white smoke and tapping sounds like you have done a head to me, white smoke is actually steam unless its bluey grey then its oil from the rings. Tapping could be pinting or pre-ignition of the fuel if water is getting into the cylinder bore. If you could post a video so i can hear it i can point you in the right direction, also how much oil did the motor burn before it stated playing up? Was it very smokey while idling / driving ??

[Alitis007]

Ab beat me by a minute lol but some good info there too

[louise]

It did burn some oil but we didn't notice any smoke coming out. The temp didn't go up, just a tapping sound, checked the oil level and it was below low mark (not good!). Smoke started the next day when started up, not really driven since then.

[louise]

We live half way between Grafton and Coffs harbour, much appreciated if you could recommend someone.

[happygu]

Hi Louise,

The best answer is to take it to a trusted mechanic, but from the sounds of it, you may not have one.

The second best answer is to get it looked at ASAP, so that you don't do any further damage to your engine.
It may well still be a minor fix at this stage, all depending if the tapping is coming from the front, high or low in the motor, or even external to the motor.

I haven't owned a 2.8 but they have known common age issues with harmonic balancers, injection pumps, heads....it could be even be something with your flywheel.

[louise]

The mechanic looking at it now thinks it is coming from the bottom, and said it would cost $10,000 to pull apart and rebuild!! Ouch!

[Alitis007]

Your description is very vague and as said before it could b s number of things but how much is a second hand engine worth

[louise]

That is the problem we are having, that is all the mechanic can tell us -'it is coming from the bottom'. He said to pull it apart, find the problem and rebuild it would cost us over $10g's. I was wondering if we can troubleshoot it first, maybe check things like compression, injectors, tappets?? I am not a mechanic - so I dont know if this is possible. The lowest quote for a second hand engine has been $7500, can you find them cheaper- as there is labour involved if we do need to replace it. Just a bit frustrated and confused as to what to do.

[Diesel-Mate]

Get a long screw driver, start the engine and put it to parts of the engine while putting it to your ear, you can then hear the internal parts moving and get an idea where the sound is comming from. Be careful around moving parts. I use this at work all the time to distinguish weird noises (mechanic). The tapping noise could be your valve clearances, but if it is a 2.8 diesel I'm pretty sure they have shimmed hydrolic lifters so they need a specialist to shimm the right clearances. Or you may have cracked your head which is common in the 2.8s. Try and find where the sound is comming from and get back to us.

Sent from my HTC Sensation XE with Beats Audio Z715a using Tapatalk 2

[nissannewby]

If your not confident with doing the above in what diesel-mate said, Getting a compression test should set you back about $100 and wont take a good mech long to find out whats going on. Injectors also are an easy item to get tested and once again a good mech with the right gear should only take maybe 2 hours to do this.

How does it start in the morning? You will be able to tell if its diesel or water thats causing the white smoke, firstly the smell will be different and secondly if its water you can get a small amount of condensation at the end of the exhaust but if your head has had it this will show up in the compression test.

The 2.8's are renowned for doing heads usually at around the 200k mark. It certainly sounds like you need to go elsewhere as the mechs seem to be looking for a quick dollar at your expense.

[BigRAWesty]

It might not be so bad. Had the same sorta thing happen in my old eb 4ltr.

Turns out it was blow by. Were the compression got past the piston, pressurized the bottom end and pushed oil into the intake.

A couple of quick tests you can do which will help you.
-Compression test..
-Pull the intake manifold off and check for oil in it.
-Take rocker cover off and check for broken springs and sticks valves..
-while cover is off check the valve stem gaps.

These will get you started cheaply.



Kallen Westbrook
Owner of
Westy's Accessories (http://www.nissanpatrol.com.au/forums/showthread.php?15134-Westy-s-Accessories.-A-small-back-yard-builder.)

[louise]

Thanks for your advice, I will get onto it.

[choppie]

To check if it's a cracked head, take radiator cap off, make sure radiator is full and start engine,
if water is pushed out of radiator or bubbles start to appear it will indicate a cracked head,
should be first test before looking internally, but agree with Diesel- mate on screwdriver or stethiscope
old mechanics trick, like Dr listening to your heart.

[Diesel-Mate]

To check if it's a cracked head, take radiator cap off, make sure radiator is full and start engine,
if water is pushed out of radiator or bubbles start to appear it will indicate a cracked head,
should be first test before looking internally, but agree with Diesel- mate on screwdriver or stethiscope
old mechanics trick, like Dr listening to your heart.

X2 with radiator bubbles

[louise]

We found a good diesel mechanic, he straight away said the bearings were shot and the piston is hitting the top part. We need a new engine, cie la vie!. He can rebuild for around $10,000 (with warranty) or can put a second-hand one (no warranty) in for a total of approx. $5000. Does this sound reasonable??

[Bob]

A seconhand 1998/2000 GU can be purchased for about the $10/13,000 mark and I would be going that way and keep your old GU for parts

[Diesel-Mate]

Yeah go for a second hand engine, there should be a warrenty for one atleast 1 month, that's what we do.