4BD1 Knocking

**mike_ie** · 24th April 2013, 08:26 PM

Well, we had planned to pull over for a few days and to post about our test run so far with the new engine, but as of half an hour ago, not so much.

Story so far is we've travelled up as far as Newcastle, about 150km north of Sydney so far, with quite a few detours along the way, with a few minor issues but nothing worth mentioning. However, about half an hour ago while driving to get a bite to eat, I started getting a squeak from somewhere under the bonnet, which has quickly turned into knocking and vibration, particularly noticeable at low revs, i.e. idle and just above. It smooths out at higher revs. I've parked up and checked under the bonnet, and I'm getting gas from the dipstick - horribly similar to the blowby I was getting on the 300tdi that just got taken out due to the engine being cooked. Can't give much more in the line of symptoms as I've not pushed the engine any further than pulling over at the first place I could get internet, but there were no overheats, no drops in oil pressure, and considering that I was testing out the engine, gauges were watched religiously.

Suggestions would be GREATLY appreciated at this stage, am hoping that someone can please tell me that I couldn't be this unlucky twice in a row, but at the moment I'm suspecting the worst....

**justinc** · 24th April 2013, 08:36 PM

Hi Mike, What year of manufacture was the engine? The pre 1988 N/A engines had non turbo spec pistons, and weren't up to big boost levels and EGT's. I have a 9/1984 build 4bd1 at 300,000km example here that has holed a piston, even running low (12psi) boost pressures and conservative fuelling.

Lots of pressure from the crank case and misfiring/ rough running. Head off and voila, a hole in number 3 and cracks in 2 of the other piston crowns.

Hope it isn't the case with yours

JC

**mike_ie** · 24th April 2013, 10:26 PM

Been chatting to the man above (JC, not THE man above

) and sounds like at least one of the pistons is not playing nice. Head's coming off tomorrow to take a look.

**isuzurover** · 24th April 2013, 10:42 PM

I would do a compression test first.

Could just be a head gasket. DaveS and I blew a non-genuine head gasket in an NA 4BD1 in the canadian rockies. Head gasket blew between 2 and 3 I recall. The engine was blowing more smoke than a steam train and had no power.

My engine is an '87 model with ~200k on the clock post turbo fitment running 21 psi Boost and no IC. Maybe I have been lucky???

**justinc** · 24th April 2013, 10:47 PM

Originally Posted by isuzurover

I would do a compression test first.

Could just be a head gasket. DaveS and I blew a non-genuine head gasket in an NA 4BD1 in the canadian rockies. Head gasket blew between 2 and 3 I recall. The engine was blowing more smoke than a steam train and had no power.

My engine is an '87 model with ~200k on the clock post turbo fitment running 21 psi Boost and no IC. Maybe I have been lucky???

Dipstick is blowing oil out of it Ben, and the provent can't cope with the pressure either

It is possible that the head gasket could've gone into a pushrod gallery but we'll have to wait and see I guess.

Damn

JC

**mike_ie** · 24th April 2013, 10:47 PM

Originally Posted by isuzurover

I would do a compression test first.

Could just be a head gasket. DaveS and I blew a non-genuine head gasket in an NA 4BD1 in the canadian rockies. Head gasket blew between 2 and 3 I recall. The engine was blowing more smoke than a steam train and had no power.

My engine is an '87 model with ~200k on the clock post turbo fitment running 21 psi Boost and no IC. Maybe I have been lucky???

Unfortunately, don't happen to have a compression testing kit in the back of the Defender, and either way, the head'll have to come off to confirm. And I'm beginning to feel a bit like the Typhoid Mary of the automotive world these days...

**isuzurover** · 24th April 2013, 10:52 PM

Bugger...

Oh well - you will get plenty of practice working on landies in people's yards...

Fingers crossed. Make sure you get the MLS gasket.

EDIT - the head is ~40kg. Don't give yourself a hernia lifting it!

**slug_burner** · 24th April 2013, 11:56 PM

Originally Posted by mike_ie

Unfortunately, don't happen to have a compression testing kit in the back of the Defender, and either way, the head'll have to come off to confirm. And I'm beginning to feel a bit like the Typhoid Mary of the automotive world these days...

You poor bastard. I feel for you.

It is just as well you have some mechanical smarts and your prepared to get your hands dirty. Still not everyone wants to spend their holidays working on a vehicle.

No one cared to mention that these bullet proof donks have an Achilles heal in the way of pistons that don't handle turboing?

**isuzurover** · 25th April 2013, 12:17 AM

Originally Posted by slug_burner

...
No one cared to mention that these bullet proof donks have an Achilles heal in the way of pistons that don't handle turboing?

I think that is going too far. There are heaps of turbo'd 4BD1s running NA pistons without a problem.

Mine in fact did the whole nullarbor sitting on 700+ EGTs before I turned the boost up and reduced them.

lokka · 25th April 2013, 12:59 AM

Mike were abouts in newcastle are you ? im at stockton if you need a hand or a loan of tools

Just give me a shout on 0401648585

Cheers
Chris

Thread: 4BD1 Knocking

Thread Tools

4BD1 Knocking

Bookmarks

Bookmarks

Posting Permissions