So, I pulled the driver’s side head and inspected the head and cylinders. You can see in the pics of the valves that the number #1 cylinder isn’t buring as well as #3 and #5. Also, number 1 cylinder looked a great deal moister inside as well. The head gasket appears fine.
I’m still uncertain what’s causing the problems as I haven’t spotted any cracks yet. As a refresher, here are the problems:
1. Some exhaust or blow-by escapes into the block and escapes out the intake manifold (or out the driver’s side head).
2. It sounds like it runs well until under pressure such as more than average acceleration, then it seems to run rough, until the acceleration is let up a little.
3. Some coolant residual appears in various places after running the engine (in the form of a slightly white foam).
4. I have leakage of slightly watered oil that leaks from the oil dipstick and from the valve cover. I can slow this greatly by disconnecting the PCV unit from the intake manifold.
Here’s a few pics (note cylinders #3 & #5 have a little liquid from pulling the head, but the #1 cylinder is much damper/oilier).
Before you pulled the head did you do a compression test? If so what was the reading compared to the other cylinders? If I understand correctly, under power/engine load the engine pops back through the intake/carb? Now if the compression was low on that hole, and it is popping back through the intake, that would be a sign of a burnt intake valve. If the compression was good but higer than the other holes, that would indacate a exhaust cam lobe for that cylinder going flat. If it can’t get rid of all the gasses after the exhaust stroke, the gasses escape into the intake during the intake stroke. (or bad lifter,but you would hear ticking) The moisture your seeing on dip stick and valve cover cap is condensation most likely. Very common this time of year, you won’t see it in summer but in the colder months it’s due to condensation in engine block. If it were a blown head gasket the oil would look like a milk shake,,,or the coolant would. Check the valves, check the cam lift on the exhaust lobe.
Hi Kenny,
Thanks for the feedback!
I did not do a compression test. That was in the back of my mind, but I decided to pull the head off first. I’ll have to get a compression gauge.
I have not hear popping through the intake. Instead, it sounds like it runs well until I push the gas to accelerate quickly. At that point it sounds as if it can’t quite burn through the gas fast enough; like it is flooding a little or the timing is off. So, I let off the gas a little, the engine seems to catch up, and then burn fine.
That said, I can see the gasses from the head area and from the intake outlet whether the engine is idling or not.
The oil hasn’t looked murky, so maybe that’s a good sign?
The engine seems to be burning through the coolant, because there is no apparent leak of any kind from the radiator, but the coolant level drops slowly, but steadily, as the engine is run.
I replaced the cam with a new cam, so I’m pretty sure the cam isn’t a problem, but you never know …
I don’t hear ticking, so I doubt it is the lifters.
The source of the problem might be in the valves as I had to replace the original head to this engine (it was cracked), so I swapped the existing valves in the bad head into the replacement head.
I’ll check into the valves as a start.
Thanks!!
= Dave
Dave
It sounds like you have a crack in the cylinder wall. I guess the compression test would tell that. If it were just a valve problem that wouldn’t explain the missing coolant. Just a thought.
Gary Peacock
That was my initial assumption. However, I have left the coolant in the engine and I don’t see it leaking into the cylinder. I also can’t spot any cracks. Of course, I suppose the crack could be fine enough that only head and pressure make it expand.
Based on several reader emails and comments, I’m going to take a closer look at the head and the valves.
Thanks!
I think your on the right track. Get the spring compressor out and remove the valves and see what the seats and valve faces look like. Now then..With what you have told me. When you get it back together take it to a shop and have the emmissions checked. You will want the CO% 1.5 to 2 % (no more than 2.5%)if it’s 5% or over that would answer the power issue. That being, when you let off it picks up power.(to rich) Anyway if it is running to rich rejet and make sure the float level is correct. Then add 2 degrees of timing to the factory spec. We have found that they respond well to that.
The other thing is. If you had a cracked cylinder or head the coolant system would pressure up. Thus blowing out the coolant. if the coolant isn’t blowing into the recovery bottle, and disapearing it has to be in a low or negative pressure point.
Hope it turns out well for you.
Hi Kenny,
Thanks again. Yeah, after looking at all the carbon buildup I see already, I am sure it is burning too rich, so I will take that advice (and, I hadn’t really spent time fine-tuning the carb, as I was puzzling over the other issues).
Some way or another, it will turn out well 🙂
– Dave