Strange clatter noise 1.6D

[aki91]

Hello guys. I have a problem with my golf for a long time.
Last year I took from him the old 1.5 engine and dropped 1.6 which I had repaired. I put new pistons, piston rings, cylinders, nozzles, took a pump specialist. But remained a problem that existed in the old engine, when starting it cold on pounding like how when gasser has pre-ignition, can be heard in the cabin while driving on certain rpm more on other weaker. When it warms up the sound disappears and works as it should. The old 1.5  clatter even when was hot,  but this works perfectly quiet hot. The engine has a compression does not consume oil is not blowing by, new nozzle are fit, the only thing that remains is the IP ... I got a second IP with a recent Golf MK 2 as it has a lever to increase your idle when pull the lever for a cold start.I will replace the pump so I'll see ...
Has anyone had this experience or is this nonsense only happen to me?

[RabbitJockey]

all of the 1.6's i have had tended to make a lot more noise when they were cold.

[aki91]

I know that they make more noise when they were cold, bad this is strange noise like detonations, and it seams that they are not appearing on every stroke, only some times. I dont know how to explane that sound, very similar whan gasser had a pre ignition...

[TylerDurden]

...The engine has a compression does not consume oil is not blowing by, new nozzle are fit, the only thing that remains is the IP ... I got a second IP with a recent Golf MK 2 as it has a lever to increase your idle when pull the lever for a cold start.I will replace the pump so I'll see ...

Were the injectors checked for "pop pressure" when nozzles were installed?

Pop pressure has direct effect on injection timing per injector/cylinder, i.e. lower opening pressure injects earlier. Matched injectors for pop pressure will help ensure injection timing is optimized evenly.

[aki91]

Yes they were pop tested. I took pump and injectors together to Bosch specialist to make sure that they work properly when i put it to new engine.

[air-cooled or diesel]

all of the 1.6's i have had tended to make a lot more noise when they were cold.

always get a 'diesel knock' when cold too, figure its normal.

[aki91]

Ok, so i freak out no reason? I dont have much experiences with old IDI engines but i love them, when he is hot it sound very nice.
Is that pump from MK2 have any advantiges on this mine 1.5  '78?

[TylerDurden]

No big worry, idi are much louder when cold.

If you have both pump numbers, it may be easier to compare; but if the MK2 pump looks mostly like the older one, it might be the only major difference is the idle levers.

Pictures of both pumps could also help.

[srgtlord]

Mine sounds like a bag of nuts knocking around until it warms up. Its an old engine design. The noise is normal

[Dakotakid]

If you are truly running an early pump and set of injectors, you may actually have one of the famed "yellow dot" pumps. And, they were a bit more aggressive.

How come guys like you that write in can never say something like:   "....my timing is set at 'X' value and my injectors were shimmed to fire at 'Y' value?

Specifics matter when worried/concerned about engine characteristics......or am I just too logical?

[ORCoaster]

Dakotakid, You are not being too logical.  But most folks don't know their timing or in most instances even how to do a proper time on their diesel.  I have no way to measure the pop off pressure on my injectors so I couldn't tell you if they were balanced against each other or not.  I could tear them apart and measure the thickness but that is the extent of numbers for me.   

Having the right tools is the biggest hurdle for us I think.  Old cars, old tech and generally old timers. 

[RabbitJockey]

yeah yellow dot pumps need to be set much more advanced, i think i had mine at 1.15mm

[aki91]

I is not a yellow dot pump, and timing is set to 0.88mm. i dont know injector break pressure because i dont have a pop tester. That is why i took them too specialist.
Thank you guys for response
I will take pictures of both pumps so you can tell mi is there any differences between them.

[RabbitJockey]

post the numbers as well.  make a video of a cold start if you can.

[Dakotakid]

See? I KNEW the guy was more knowledgeable than he let on!

If the cold start snap is causing you social problems (neighbors call the police every time you fire it up), you can make sure the hood liner/sound-deadener stuffing is still intact or even add some additional material to the underside of the hood. That helps to a certain extent. Using a block heater for cold starts also helps to "tone-down" the racket. Also check to see that your valve clearances are properly set (if you are running a solid head).

0.88 mm is fairly vanilla ice cream on pump timing. That shouldn't be too much of a factor in creating anarchy. My 1986 specific-model XXX-XXX-081C pumps are notoriously loud at cold start. I don't sit here at the house and annoy the neighbors.....I get underway asap and warm the engine up much farther down the block if needed. All part of running these dinosaurs.