Author Topic: loud engine (Read 2476 times)

MattRabbit · « **on:** January 02, 2006, 11:54:54 am »

Ever since I've raised my Rabbit from the semi-dead, it's been really loud when cold. I mean REALLY loud. It sounds almost like something's loose in there, almost like the exhaust is rattling around. Once the car warms up, it sounds perfectly normal. I'm not sure what could be causing that, but it wasn't that loud before.

I'm wondering if the injectors are nearing their time of replacement. For all I know, they're the original ones at 315K miles. Could this be part of it?

mk1vdub · « **Reply #1 on:** January 02, 2006, 04:25:59 pm »

if its cold and you have the cold start handle pulled out - one of the things this does is advance the timing which will make it sound much louder and 'clackety' as it warms up if you then push the cold start in it will quieten down.
it would certainly do no harm to have the injectors pop tested
is it a hydralic tappet head? if so these can get blocked and become louder

vwmike · « **Reply #2 on:** January 02, 2006, 11:59:00 pm »

It's a Rabbit so it probably has solid lifters (that is unless someone swapped in a hydraulic lifter engine). The solid lifters can also be ite loud when not properly adjusted. It's usually difficult to hear over the diesel clatter though. This would quiet a bit as it warms up and the tolerances become tighter.

As for hydraulic lifters - those usually collapse after a while and start to make more noise. I actually pulled my cam out when I had the head off a few weeks ago figuring there was a bad lifter because all I could hear was one making noise. Turns out ALL of them were collapsed and bad.

Do you have any troubles getting the car started when it's cold out?

MattRabbit · « **Reply #3 on:** January 03, 2006, 10:11:11 am »

It's the original engine, so it's definitely solid lifters. I haven't adjusted them yet, so that might be a good idea.

I have no problems starting the car at any time. It has excellent compression. It just is really noisy when it's cold. I'll adjust the valves and check the injectors to see if that helps. It definitely can't hurt!

mortskeg · « **Reply #4 on:** January 03, 2006, 12:33:50 pm »

MattRabbit-
I had a similar problem with my original 1.6- very noisy on startup. My friend suspected the valve clearance as well, so we checked it with the feeler gauges. Turned out that the valve specs were right on but the fuel timing was off (by almost a tooth IIRC). I would also check your valve clearance first, but if these are ok I'd get out the timing tools. It will sound different though with the CS knob out.

Hope this helps.