Blown head?

[Surly_Z]

Car started a little rough a week ago, so haven't started her up until yesterday. Symptoms are as follows:

- loss of power

- loss of oil, around 700ml

- loss of 1/4 of coolant

- oil is darkish, but no smell or trace of coolant

- coolant is green, has a tinge of brown but I think it may rust from radiator not oil.

- NO overheating

- Oil pressure was good until it ran rough.

 

Funny thing is that I knew there was a small oil leak at the sump, but not enough to worry about. No visable external water leaks either.

 

 

Posible head gasket problem?

[C.A.R.]

Do a compression test to confirm, Josh.

[chris240]

joshy joshy, that head of yours has been stuffing with your head for ages now 

symptoms arent good. Must be that Melbourne climate...

chris

[Surly_Z]

joshy joshy, that head of yours has been stuffing with your head for ages now 

symptoms arent good. Must be that Melbourne climate...

chris

 

This is the "newer" engine. Was running perfectly, apart from needing the inlet manifold needing two new bolts.

 

Lurch, you're right - I'll do that and let you know how I go.

[Surly_Z]

Do a compression test to confirm, Josh.

 

Ok, have completed a compression test. Results as follows:

 

#1 = 120 psi

#2 = 110

#3 = 110

# 4 = 110

# 5 = 115

# 6 = 115

 

This was a dry comp test, as my battery ran flat before I could do a wet one.

 

Firstly, these seem to be pretty low numbers right? Shouldn't I be looking for 140-160 usually? Or at least about 120? If I can get my battery charged (leant my jumper leads!) I assume then these numbers would increase across all 6?

 

I guess it's "good" that there is no significant difference between all 6? All 6 sparkies look fine too.

 

All I can guess is that it my be my dodgy intake and exhaust manifold which may have a small leak or two. I'd rip it off, but I need to get two bolt drilled out, plus some custom washers due to a 5mm difference between intake and exhaust manifold thickness.

This doesn't explain the power loss on opening the throttle.

 

Any ideas?

[Scoota G]

The engine is down a bit but they are all around the same which is a good sign.

[Zedman240®]

I'd be checking the ignition system; cap, rotor and leads etc. If it happened all of a sudden, could be as simple as a faulty part.

[Surly_Z]

I'd be checking the ignition system; cap, rotor and leads etc. If it happened all of a sudden, could be as simple as a faulty part.

 

Sparkies are new. Cap and rotor are fine. Leads haven't been changed in 3yrs.

 

Still doesn't explain my missing oil and water!

[Zedman240®]

All engines use oil and water; it's just at what rate they do lose it at that can be worrying. Check carby linkages and give them a good soaking of spray oil to make sure nothing is stuck or sticking. Just a guess!

[Surly_Z]

All engines use oil and water; it's just at what rate they do lose it at that can be worrying. Check carby linkages and give them a good soaking of spray oil to make sure nothing is stuck or sticking. Just a guess!

 

I will do, and let you know!

Thanks

[Ben]

Try a leakdown test - that will show you which cylinders are bleeding pressure, where.

 

But those comp numbers are very low - almost down to 'beyond serviceable limits'. If they don't come up with a wet test, then you've got some significant wear'n'tear in the old girl (lots of ring clearance, trashed head gasket, cracked pistons or burnt valves). If they come up, then it's tired rings - but don't expect 180's across the board, it sounds like that donk needs a refresh.

[Surly_Z]

Try a leakdown test - that will show you which cylinders are bleeding pressure, where.

 

But those comp numbers are very low - almost down to 'beyond serviceable limits'. If they don't come up with a wet test, then you've got some significant wear'n'tear in the old girl (lots of ring clearance, trashed head gasket, cracked pistons or burnt valves). If they come up, then it's tired rings - but don't expect 180's across the board, it sounds like that donk needs a refresh.

 

yeah maybe, but it was a strong motor and then literally overnight it does this. My old engine I knew was "wearing" old gradually, this one just seemed to play up at a sudden. I'm starting to think maybe it a fuel delivery thing as Dimitri suggested. I'll check it put again in the morning.

[Surly_Z]

Sigh..... I hate when this happens! The engine has sorted itself overnight....!

 

Checked linkages as Dimitri suggested, and they were all fine.

 

All I can guess is that is something in the ignition system, as I had to disconnect coil, cap and dizzy in order to do the compression test yesterday.

 

Dimitri, you think I should put that spare electric dizzy on? Maybe that and new leads it may sort the issue.