Author Topic: Can thickness of head gasket contribute to no start? (Read 3968 times)

tomw64 · « **on:** April 06, 2008, 11:30:59 pm »

I have a 78 rabbit diesel, 1.5 liter. I had to replace the head due to a tragic incident involving the tension pulley falling apart. The first head I tried turned out to have a crack in it. I found a new MCI head in a car that would not start, the person who sold me the head said it was the block that was bad. So now I installed the head and everything is turning over, but no start, not even with a little starting fluid. I already checked the glow plugs. It could be air getting in through the injector pump (I use biodiesel and the injection pump might need rebuild), but I just wanted to see if I could rule out the head gasket size. I put a five notch in there, would this cause low compression hence no start if it is too much clearance.? I'm not an expert, but I've been through a few gasket replacements with success. I'm at a loss here, maybe the head is the issue since the last car would not start. Is there a way to tell if I have the right MCI head for a 1.5 liter, maybe it's a 1.6 liter head. Any suggestions?

truckinwagen · « **Reply #1 on:** April 06, 2008, 11:48:32 pm »

if the gasket is too thick it will lower compression and maybe keeo it from starting. next time you have the head off check the piston protrusion past the block to verify what gasket to use.
the 1.6 head has slightly more volume in the prechambers so if it is a 1.6 head compression will be lower from that too.

jtanguay · « **Reply #2 on:** April 07, 2008, 07:24:49 am »

it will kick with the quick start if everything is as it should be. if not then something is out of whack, and my first guess would be compression. (do not use glowplugs when using quick starting fluid... the gp's will autoignite the fuel at the wrong time and could possibly burn them out)

so if its kicking with quick start, then move on to fuel system. loosen injector nuts and confirm fuel is coming out when cranking.

tomw64 · « **Reply #3 on:** April 07, 2008, 07:01:42 pm »

Thanks for the advice. I figured it is a compression problem. Everything turns over fine but no explosions. I'll try to locate a compression test kit to verify if it is or not.

jtanguay · « **Reply #4 on:** April 07, 2008, 07:13:07 pm »

it could be that some valves aren't sealing properly.. resulting in bad or even no compression.

tomw64 · « **Reply #5 on:** April 08, 2008, 01:52:31 pm »

meaning bad head, or could this be attributed to the gasket?

tomw64 · « **Reply #6 on:** April 11, 2008, 01:46:28 pm »

I found out that the gasket thickness is only determined by the piston, and has nothing to do with the cylinder head. Since the last person who tried this particular head had no luck I'm starting to think it's the head itself. Time to take it off and bring it over to the head shop.

saurkraut · « **Reply #7 on:** April 11, 2008, 05:04:18 pm »

I think you want to take it to a machine shop. The guys at the head shop will probably say 'Oh wow man, is that a 4 holed roach clip?' :wink:

http://en.wikipedia.org/wiki/Head_shop

tomw64 · « **Reply #8 on:** April 11, 2008, 05:19:36 pm »

Good point, there's plenty of those here in Portland. But we also have the aluminum head re builder's shop which comes in handy for other issues involving smoke.