Low compression in 2 cylinders.. ::sigh::

mixwell · Jan 2, 2009

Well I did a compression check and I'm showing Cylinder's 1 and 2 are low. While the others average about 150, cylinder 2 is @ 120 and cylinder 1 is @ about 75 !! I have the Hayne's manual and it is suggesting that a worn came lobe could be an issue if 1 cylinder is below 20% of the others.

I have also read that when 2 cylinders next to each other are low it could indicate a blown head gasket. I plan on having some help to remove the head tomorrow but I was going to take it to a shop to get a head job done since if I have to replace the gasket might as well get it all done legit. Anyone have similar issues ? Any insight is appreciated. Thanks in advance !!

By the way its a v6 3.0 (2001 Ranger)

-- MixweLL

Wicked_Sludge · Jan 2, 2009

a worn cam lobe wouldnt be high on my list of things to check...but its not entirely impossible.

i would follow up your dry compression test with a wet compression test and possibly a leakdown test.

mixwell · Jan 3, 2009

Thanks for the input. On the cylinders that were "dry" once I squirted some oil in the cylinder they did go up, however the number 1 cylinder was still quite low.. Seems odd for a worn lobe to just go out automatically like that isn't it ? I wouldn't figure it would just happen all the sudden but I don't really know anything about cars to be honest.

Anyways I got the head off today and of course by that time most shops were closed and with Sunday.. So I will probably have to wait until Monday to take it in. I really wanted to avoid having to get a rental car but looks unavoidable.

Wicked_Sludge · Jan 3, 2009

if compression was still low with a wet test then the bottom end is probably fine. check your head gasket very closely around the suspect cylinder(s). you can usually see a blown head gasket after the head is removed.

mixwell · Jan 3, 2009

I don't think the gasket was blown but looks like in cylinder 2 there was some rusty coloring by one of the valves (the smaller one) However cylinder 1 is the low compression cylinder. I've also noticed that the spark plugs in cylinder 2 and 3 looks really dirty compared to cylinder 1 (the low one) which I have no reason why. I will go down and take some pictures in a few minutes. Ill post shortly.

Wicked_Sludge · Jan 3, 2009

a nice clean spark plug is usually an indication of coolant getting into the chamber and keeping everything nice and clean.

mixwell · Jan 3, 2009

Now that I look @ it the larger valve on cylinder 1 seems to be "moist" while the others are not.

Complete view of the head

Cylinder 2

Head Gasket

Cylinder 1

Wicked_Sludge · Jan 3, 2009

the picture is fuzzy, so its hard to tell; but is that a crack running from the #2 exhaust valve (the smaller one) downward towards the coolant passage?

ibleedblue · Jan 3, 2009

sure looks like a crack to me

mixwell · Jan 3, 2009

Wow.. Good eyes you all !! Never even suspected or noticed that. After take a closer look it does appear it is cracked and I scrubbed the crap outta it just to make sure. see the picture below. I am 99.9% sure it is crack.. So if thats the case what do I have to do ? Purchase a new/salvaged head or what ? Ya. I just looked at the photo in the full view and up close I can actually see the crack and where the metal is seperated..

crazy zoomed in picture.. you can see its cracked for sure..

plainsranger · Jan 3, 2009

You did pull both heads off right? (assuming you did to change head gaskets but wanted to make sure). Check the other head carefully for any signs of a crack cuz if one did it the likelyhood of the other side cracking is very good. Time to purchase new heads, (not rebuilt) and slap them on.

Wicked_Sludge · Jan 3, 2009

you can either go the route of a rebuilt head, or you can get a junkyard head and go over it yourself. the former is easier, the latter will likely be a little cheaper...especially if you find an engine with relatively low miles.

i personally wouldnt waste my money on new heads. the 3.0 isnt "known" for cracking heads like the 2.9, so theres really no advantage to spending the extra mulah.

its time to take a close look at your cooling system, however. heads dont usually crack for no reason. from what we can see in the pics, the cooling passages seem to be pretty clean, but the radiator might not be in as good of shape. a worn water pump, stuck t-stat, weak radiator cap, or too much antifreeze-to-water ratio can also cause problems.

mixwell · Jan 3, 2009

I hate to admit it but seems like neglect on the cooling system on my part.. The coolant looks like chocolate milk.. since cylinder 1 and 3 were on the same head, that is only one i have taken off.. I initially planned on keeping the drivers side head on but after reading should I go ahead and take it off as well ?? I'm pretty sure I know that cause of the crack is lack for the cooling system.. To Begin with my oil was low about 3 quarts and my coolant hadn't been changed I don't think since I bought it in 2001.. I know I know i am a Fking idiot but I will never make this mistake again.. Stupid mentality thinking a "new car' (when I bought it) doesn't need care and proper maint when suggested because it is new and "I can driver it longer before maintenance" god... I am disappointed in myself for letting it get this bad to be honest.. :dunno:

mixwell · Jan 3, 2009

plainsranger said:
You did pull both heads off right? (assuming you did to change head gaskets but wanted to make sure). Check the other head carefully for any signs of a crack cuz if one did it the likelyhood of the other side cracking is very good. Time to purchase new heads, (not rebuilt) and slap them on.

No I haven't pulled both heads.. I still need to go to the auto shop store and purchase new gaskets.. the work I did today was all taking apart crap.. I really hope both heads aren't cracked.. I will have to wait and check tomorrow though. Time to browse online and see what new heads cost ::sigh::

Wicked_Sludge · Jan 4, 2009

definitely pull the other head. your already this far and with the damage so far, its not worth risking it. give the passanger head a very thorough inspection for even the tiniest little crack.

dont forgot the head bolts need to be replaced on both sides before re-assembly. the bolts are a special torque to yeild design and can only be used one time.

and dont feel bad about neglecting the truck. now you know what the consequences of neglect. just make sure you learn from your costly mistake and dont do it again.

Low compression in 2 cylinders.. ::sigh::

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