The Clymer repair manual says "Difference between cylinders should not exceed 14 psi". However my experience with a variety of 4, 6 and 8 cylinders is that good used engines with more than 100k miles will be within 5 psi of each other.

ive had similar symptoms (not knob on the exhaust but if thats what hes into )

was when i rerouted the pcv valve and rocker cover breather to my catch can, pcv jamed open causing condensation to build up under rocker cover and cause that lovely gooy mess (again not knob related) uder rocker cover, oily smell and white (slight steam) from exhaust.

best way to tell is to put your knob on a hot exhaust untill you smell a nice roast.

There should not be more then a 25% variation between cylinders. If it is well and truely blown there will be very little comp in that pot if any! Others will be from 120-170 depending on the state and type of engine.

And if there is 1 pot with low comp, run the car for a while untill its warm and the cooling system is at max pressure. Then turn the car off and wait 10mins. Now take all the plugs out and get somebody to turn the car over while you hold 1 big peice of paper/clean rag over all the spark plug holes. If it is blown water would have seeped into that cyl in the 10mins and then be blown out onto the paper/clean rag. Then you can see it and be sure of the problem.

What type of car is it? You mentioned late modle EFI.

Chemiweld would probably do SFA to a blowout that severe!

You will be looking for one cylinder that is lower than the other three. Check the factor (or Gregory's) book for exact specifications.

If all four cylinders are nearly the same, that is good.


Recommend you do not tear the engine down until you find the problem. We worked on a Camry summer before last with these symptoms, and it was a leak from the intake manifold into the water passages (coolant-heated manifold).

thats exactly where i thought its blown
ill do test tomorrow
what is a normal reading for this type of blown gasket on a latermodel efi car
a big or smallish drop in pressure

thank you

Yes I've seen these symptoms several times. There can be a leak in the gasket between the cylinder and a water port, but (not yet) a leak between an oil passage and water passage.

Do a compression test, first thing off. It costs nothing and will tell you if there is a compression problem.

most cars dont when its 35degrees outside
none of my cars do anyway when its hot

and for radiator
its not blocked as its a brand new alluminium radiator

ill give search a go

but if any is aware how it is when a bhg is in early stages tell me cause most my bhg have been rather big blows

cars blow white smoke when u first start them, thats just coz its cold..

hmm for rad, mabe its blockd?

try seach buttom mabe it has covered before..

water in oil system (cam covers breathers sump etc)

oil in water system(radiator etc)

white steam from exhaust

radiator bubling or presurising

now for my question
its bubbling in radiator when i start engine
its blowing white smoke
but none of the above symptoms
oil is not burning and is clean(no water)
no blow by or pressure up top when i take cap off oil fill location idles fine etc..etc..

is this a bhg in the early stages???
has any1 had this before???
i have had plenty of bhg over time but never this small of problem
usualy it uses heaps of water or mixes with oil and i change straight away but this aint as bad???