Holden 253

**mickstv** · 18-12-16, 03:20 PM

My old Kingswood has a 253, anyway it had been running fine up until today. At idle the motor is making a farting type noise out of the odd side exhaust, if you increase the rev's upto 2k it starts backfiring. At the same time a-lot of moisture is coming out of the odd side, but no blue smoke.

A removed the spark plugs on the odd bank and no1 is clean but 3,5 and 7 are gummed up + oil on the threads. Cleaning didn't fix the fault.

Anyone got any ideas ?

Edit... The problem is more prenounced when running on petrol.

**Bigfella237** · 18-12-16, 06:09 PM

If you're lucky it may have just blown a head gasket, are you losing water from the cooling system? And/or getting a lot of bubbles up through the radiator when the motor is running with the radiator cap removed (be careful if hot)? And/or getting contaminates in the oil (milky foamy looking oil on the dipstick)?

But it sounds more like it may have burnt an exhaust valve?

Either way a compression test is the next step, you will likely find one (or maybe two adjacent cylinders) has no compression. If that's the case then the cylinder head has to come off and it should then be obvious what the problem is.

Andrew

**mickstv** · 18-12-16, 06:15 PM

Thanks, for the reply. I checked the radiator, no bubbles but it has used a little water from the overflow in the last week, maybe 1/4 litre. Dipstick looks fine. I'll have to find some who has a compression tester.

**Bigfella237** · 18-12-16, 06:47 PM

A 1/4 litre is nothing really, if coolant was getting into the cylinder it would be using something in the order of litres per kilometre and blowing steam out that exhaust. But there's several different ways a head gasket can blow, either coolant passage to cylinder, or cylinder to cylinder, or cylinder to atmosphere (this last one sounds like a bad exhaust leak under the exhaust manifold).

I've had Holden V8s all my driving life and blown a few head gaskets over the years, but yours sounds more like a burnt valve, the exhaust will be making a "pfft pfft" kind of noise every time that cylinder fires.

Another very common thing they do is wear the lobes off the back of the camshaft due to lack of oiling, but that affects the rear cylinders and it doesn't happen all of a sudden.

Andrew

**mickstv** · 18-12-16, 08:08 PM

I'll do some checks over the next few days and post what I find. Thanks again Andrew.

**Godzilla** · 19-12-16, 12:34 AM

Check your oil if its turning white.

If its backfiring and you run LPG you may have a timing or spark issue (coil, leads plugs)

It may also be getting tired as LPG is known to cause valve seats to get tired.

Backfires can also blow out intake manifold gaskets which can help oil get into the intake plenum to head seal.

**mickstv** · 19-12-16, 07:04 AM

Hi Godzilla,

The oil looks normal.

All the leads measure 1.5 to 2.5k so thats normal. and has a new coil on it and timing is fine.

The heads have got hardened seats etc for gas.

Going to have another look at it tonight, when I get home.

**lsemmens** · 19-12-16, 10:36 AM

How many miles has it done?

**Tiny** · 19-12-16, 04:45 PM

I'd go buy yourself a compression tester, they are not expensive (~$60) for a reasonable handyman quality unit..
It will give you more scope for diagnosis of the issue.

**mickstv** · 19-12-16, 05:30 PM

Originally Posted by lsemmens

How many miles has it done?

Done about 73000km's since the motor was rebuilt (honed, rings, bearings, cam and heads rebuilt etc.)

Originally Posted by Tiny

I'd go buy yourself a compression tester, they are not expensive (~$60) for a reasonable handyman quality unit..
It will give you more scope for diagnosis of the issue.

I see supercheap have some kits, I guess it will be an early Christmas present.

**Godzilla** · 21-12-16, 05:02 PM

If you have a air compressor at home buy yourself a leakdown tester.

I only use a compression tester when away from home with no access to air.

Leak down testers nail how much wear and from where the issue stems from, if the result is low you can listen in the oil filler hole for hissing pointing to worn rings and bore, intake hissing points to intake valves, exhaust hiss points to exhaust valves.

**Tom Mix** · 21-12-16, 05:51 PM

Originally Posted by mickstv

My old Kingswood has a 253, anyway it had been running fine up until today. At idle the motor is making a farting type noise out of the odd side exhaust, if you increase the rev's upto 2k it starts backfiring. At the same time a-lot of moisture is coming out of the odd side, but no blue smoke.

A removed the spark plugs on the odd bank and no1 is clean but 3,5 and 7 are gummed up + oil on the threads. Cleaning didn't fix the fault.

Anyone got any ideas ?

Edit... The problem is more prenounced when running on petrol.

I would replace the gummy plugs 1st then if necess go on to leakdown tester &/or comp tester.

**mickstv** · 23-12-16, 06:28 PM

Well comp test didn't show any problems, next I removed the intake and found a small amount of oil under the gasket around 3,5 and 7. So I replaced the gaskets and faulty sparks plugs, seems to be running fine at the moment. In a week or two I'll recheck the plugs.

Thanks for the replies, Merry Christmas to you all.

**hazman** · 23-12-16, 07:09 PM

I add this to everything I have that runs on petrol they never miss a beat,used to have problems with mower and line trimmer plugs oiling up and Gen3 commodore missing at high revs. I add about 3 tablespoons to a 60 liter tank of fuel on the commodore.

**mickstv** · 23-12-16, 07:28 PM

I'm running a flashlube kit. Same as the one linked below.

**LeroyPatrol** · 25-12-16, 07:22 PM

time for a 308.....never late in a 308

......Leroy

**Joseph2** · 07-02-17, 07:29 AM

hey mate sounds like the rings on there way out but a definite on leaking vlaves. i would recommend new valve guides and vlaves with new seals. have you done a comp test yet? also the fuel? do you have the SS valves or are they the original ones? with older vlaves you need the valve saver fluid with petrol or the valves will just flog out

**RedXT** · 12-02-17, 01:52 PM

Originally Posted by LeroyPatrol

time for a 308.....never late in a 308

......Leroy

totally agree

**mickstv** · 07-03-17, 01:57 PM

Thought I had better report in, sparks plugs are still clean and motor is running fine.

I do have another problem, the 10yr old radiator is starting to leak on the top bowl. Was quoted $160 to drop the top and bottom off and rebuild if everything else looks ok. Should I spend $160 on it, or spend a few extra $$ on a Aluminum Radiator, like the one in the link below.

Opinions Please....

**Rick** · 07-03-17, 02:46 PM

Originally Posted by mickstv

Thought I had better report in, sparks plugs are still clean and motor is running fine.

I do have another problem, the 10yr old radiator is starting to leak on the top bowl. Was quoted $160 to drop the top and bottom off and rebuild if everything else looks ok. Should I spend $160 on it, or spend a few extra $$ on a Aluminum Radiator, like the one in the link below.

Opinions Please....

Ive bought several radiators from this seller, very fast service, and they are of a high standard, ive had one in my 80 series cruiser for 2 years now and it still looks new, spend the extra $14 old boy, you'll be glad you did