Blown Head Gasket?

S

sven

Member
Hello,

So here are my symptoms:
Hard start
Lots of white smoke at start
High EGT temps- can hang around 1400
"Lurching", slight inconsistent power, nothing super dramatic, just climbing a hill or accelerating i feel slight times of extra pulling, almost like a pulse.

Reasons I'm not sure
Coolant temp never gets above 200 degrees
No coolant loss
No milky oil
White smoke goes away after time, but might come back after coming to a full stop.

I'll post of video of the hard start later today.
Hoping it's just unburnt fuel and that would be fixed with IP timing?

Thanks
 
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No coolant loss. No milky oil. I'd say no blown head gasket.

When I blew the head gasket on my L300 the first symptom I noticed was a loss of coolant via the burning of the coolant in the combustion chamber, pressurized coolant hoses, and it was pressurizing the system so much it was dumping coolant overboard out of the expansion tank.

I would check glow plugs and IP timing for the smoke during startup issue. I would check turbo (turbo vacuum lines, wastegate, boost compensator; low or inconsistent boost could cause high EGT or inconsistent power) as well as injection timing.
 
Glow plugs are new.
My boost gauge reads pretty normal. Don’t get above 9 psi but it doesn’t fluctuate but not sure how fast the gauge changes.

I’m planning on doing a long road trip soon so idk if I should mess with the IP timing… but also not sure if I should even drive it with egt temps getting so high.
Am I ok as long as my coolant temps stay ok?
 
How high is high? You can check Ip timing with a tool from Bosch that can be bough off amazon. Theres an adjustment spec in the service manual.
 
Curious about the EGTs being so high (1400F), how long are you letting it stay that high? If that is an accurate temperature I would be worried about melting something if you are that hot for very long?
 
sven said:
Am I ok as long as my coolant temps stay ok?
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No.
The problem with high EGT's is twofold. Very high EGT's (1400-1600˚ f +) can melt the turbo's exhaust driven turbine fins. This throws the turbine out of balance, it then destroys itself, and in the process the compressor fins can fragment and take out your engine; and it can cause the turbo to dump a bunch of oil into the intake causing an engine runaway.

The second issue is heat soaking and coolant cavitation. If engine parts (the head in particular) heat soak to different temperatures, they will then be likely to cool down at different rates. This leads to warping and cracking.

Coolant temp is more of an average measurement; EGT is a specific measurement of one aspect. You want both to be within "normal" ranges.
 
I don’t let it stay there for more than 15 seconds. But I need to address it before I need to make any serious climbs. I’m guessing I need to tackle my boost pressure.
 
1400˚ cruising at 100k is high unless you are actually on a long incline. IDT boost pressure is your problem.

I'm wondering if your EGR valve may be stuck open or malfunctioning... that can cause hard starts and poor acceleration (it is supposed to be closed then).
 
sk66 said:
1400˚ cruising at 100k is high unless you are actually on a long incline. IDT boost pressure is your problem.

I'm wondering if your EGR valve may be stuck open or malfunctioning... that can cause hard starts and poor acceleration (it is supposed to be closed then).
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EGR is deleted. Hard starts are actually not too consistent. Tried to get a video yesterday and it was fine… and it was relatively cold. 35-40f
 
sven said:
EGR is deleted. Hard starts are actually not too consistent. Tried to get a video yesterday and it was fine… and it was relatively cold. 35-40f
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Then my next guess would be IP timing... are the symptoms new or gradually developing/getting worse? What year is your van?
 
sk66 said:
Then my next guess would be IP timing... are the symptoms new or gradually developing/getting worse? What year is your van?
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1993.
Hard to tell honestly… the white smoke has been happening for a while though. But I’ve fixed some other issues. It used to blow white smoke all the time but I cleaned the injectors and that helped. But I had power loss because of a stupid issue so I never was able to get it up to speed and see the egt temps so high. To mess with IP timing the first step is to get my boost up to 12 psi right? Or due to my issue I should just start retarding the timing without addressing boost
 
sven said:
1993.
Hard to tell honestly… the white smoke has been happening for a while though. But I’ve fixed some other issues. It used to blow white smoke all the time but I cleaned the injectors and that helped. But I had power loss because of a stupid issue so I never was able to get it up to speed and see the egt temps so high. To mess with IP timing the first step is to get my boost up to 12 psi right? Or due to my issue I should just start retarding the timing without addressing boost
Click to expand...
The first thing is to verify the IP timing by aligning all of the timing marks. Next thing to check would be that the IP position doesn't seem to have been changed/shifted. You do not need to increase the boost pressure to set the IP timing... if it is blowing a lot of white smoke the chances are that it is already too retarded; not advanced.
But IMO, if you can't find an apparent cause of the timing to be significantly off, the issue is probably internal (if it's not the injectors still).
 
sk66 said:
The first thing is to verify the IP timing by aligning all of the timing marks. Next thing to check would be that the IP position doesn't seem to have been changed/shifted. You do not need to increase the boost pressure to set the IP timing... if it is blowing a lot of white smoke the chances are that it is already too retarded; not advanced.
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sk66 said:
But IMO, if you can't find an apparent cause of the timing to be significantly off, the issue is probably internal (if it's not the injectors still).
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So the timing seems fine as far as I'm aware. And the IP timing doesn't seem to have changed or been messed with.... Should I try my hand at shifting the IP or should I mess with the full load/mixture screw?

I'm fairly certain my injectors are ok...I took them out and had them professionally refurbished. I was a having some version of this problem before doing that. Any other internal issues I should consider?
 
sven said:
So the timing seems fine as far as I'm aware. And the IP timing doesn't seem to have changed or been messed with.... Should I try my hand at shifting the IP or should I mess with the full load/mixture screw?

I'm fairly certain my injectors are ok...I took them out and had them professionally refurbished. I was a having some version of this problem before doing that. Any other internal issues I should consider?
Click to expand...
You can often/usually adjust the IP to gain a bit of performance increase; but if things are w/in OEM adjustment it should not be causing performance issues.

Check the outlet banjo for blockage, I believe that can cause a pressure increase which will shift the IP timing internally. Other than that, at this point I suspect internal IP damage. But I am not an expert on injection pumps by any means... hopefully @Scott will chime in.
 
When you check the return banjo bolt, look for metal flakes. We have seen the camplate in the pump fail and send metal into the advance piston area. It will cause the piston to stick and have high egt's and low power. Kellyn's 4M40 did this.
 
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