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Hi Everyone,
I fix my car the other week, then my mom drops hers off because of no-coolant…again.
I filled it up with water (DON’T hate, it’s just for the test). There were no leaks at the coolant reservoir, lines to the radiator or into the engine. I know that the 3.5L engine can have leaks at the “heater feed hose” under the intake manifold. When I called the dealer this problem is only on the 2.7L engines, not the 3.2 or 3.5L. I followed this up with a compression test as I do see white smoke from the exhaust. The smoke does not appear to be of a significant amount though and only during start up, so I don’t believe a head gasket leak would account for a substantial enough loss to have no coolant in a short time.
The compression test showed between 80-90 PSI on the first stroke and by the fourth stroke was at 145-150 PSI for all cylinders. None appeared to be labored in achieving the 150PSI. I am going to stop at NAPA today to buy a head-gasket leak tester.
Questions:
1) Can I have good compression and still have a faulty gasket or warped head or block?
2) Has anyone worked on the Chrysler 3.5L engines and have an idea on what feeder tube I am talking about?Best,
Steven
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Rent a pressure tester from an auto parts store and pressure test.
You could have a bad cap.here is a link to further help.I thought I had a bad head gasket on my Subaru and was preparing to pull the engine. But first I decided to do a pressure test. No leaks and it held pressure (15 psi). So I let it sit. Half an hour later the pressure was down and it was leaking antifreeze. I traced it to a leaky hose.
So, a pressure test saved me a good deal of work.
That’s my thoughts. I’ve hit up three stores here, and none have the pressure tester available for rent or purchase (many employee’s didn’t even know what I was talking about). I’ve got the block tester to at least rule out the head gasket, but imho it’s likely been warped (my mother has a terrible record with maintenance, and the 3.5L doesn’t take kindly to that)
On my way to the boys.
The last pressure tester I got I had to order and then when I got it I had to order adapters to fit my car. No store here had one either. Nevertheless, a nice piece of kit to have.
Alright, I have a diagnostic update and need some help with the next step. I will put all the information below that I think may be pertinent for you to help.
1. 2004 Chrysler 300M Special 3.5L with 189,600 miles
2. Has overheated in the past (aluminum cylinder head, I believe the block as well)
3. Overheated, was low on coolant
4. Due to the substantial amount of coolant around the engine bay, it was assumed a coolant system leak
5. Pressure test performed: a pressure of 16.5PSI was held for 40 minutes, no leaks could be seen
6. Compression test showed no “bad” cylinder (all hit 150PSI by the 4th stroke)
7. Block test showed a combustion leak into the coolant
8. no coolant observed in the oil (and no oil in the coolant)
9. no noticeable performance issuesWhat is the next diagnostic step, or is there not much I can do until I start taking it apart? Can I distinguish between a bad gasket, warped or cracked head cylinder? If I understand the leakdown test correctly, it will tell me which cylinder(s) are the problem, not the exact nature of the combustion leak is.
Also, if the cylinder head is bad (warped/cracked) is it possible the block is still good, or will the block also warp with the cylinder head?
The post of the guy with the jeep head cylinder/gasket problem seems to have answered mine as well…II need to start removing stuff :(…then hope I’m not SOL
Everybody is always looking for coolant in oil or oil in coolant but the most common head gasket problem these days is products of combustion to coolant. And it is also common for the head gasket to seal on a pressure test but leak when the engine is running. Sometimes it only leaks at WOT making things even more confusing because the owner may drive for days without encountering the problem.
I was thinking of suggesting you increase the torque applied to the head bolts. Doing this has three possible outcomes: 1. it is fixed, 2. no change and 3. you wreck the threads in the block.
Interesting suggestion, but if the cylinder head isn’t warped, I would think that tightening the headbolts would risk bending the block. I was looking for coolant/oil mixture because of experience with this before. =
[quote=”KingMeander” post=87628]Interesting suggestion, but if the cylinder head isn’t warped, I would think that tightening the headbolts would risk bending the block. I was looking for coolant/oil mixture because of experience with this before. =[/quote]
If the block test was positive. Time for the head to come off.
check the head and block with a straight edge. You might get
lucky and only need the head gasket. Keep us posted on your progress.Yea, if you tested positive for combustion gas in the coolant, it’s time to remove the head and have a look.
Keep us posted.
I finally had time this weekend to remove the heads (wow…Chrysler makes their engines a pain to work on). The pistons and heads themselves looked spectacularly clean for having 189,000 miles (I could see most of the aluminum!)
The right head had a low spot of 0.005″ at cylinder 3, while the left head was roughly 0.001″. According the specs, the tolerance is 0.002″ for the head or the block. The heads are being machined at NAPA and a pressure check performed.
The block on the left was golden, and on the right showed just under 0.002″. I know I should remove the block to do the job right, but I don’t plan on it at this time.
The question I have is will removing that extra material from one side affect how the car runs, or is it not significant enough to warrant concern.
Yes, if you remove material from one cylinder head, the same amount should be removed form the other head. Engines need balance to run smoothly, if one side has higher compression than the other, it will be out of balance.
Keep us posted.
Hi all,
All my parts have or should arrive today for me to start putting the engine back together. I have a question regarding installing the head gasket.
A MasterTech video by Chrysler states to spray the head gaskets (MoparPerformace ones I bet) with copper spray equivalent. I don’t recall copper spray being on the old gaskets when I removed them, nor does Victor-Reinz mention or my service manual mention that I should be putting copper spray down. Does anyone have thoughts on this? Should I spray the block side since it was not machined down and leave the cylinder head clean?
Also, I have some rubber O-rings that need to be replaced on the rear-timing cover for the coolant passages. The dealer doesn’t have them/couldn’t find them. These aren’t small O-rings either (about 1/4″ thick) and no parts stores had anything either. Can I use RTV gasket maker to form my own “O-rings” or is this a bad idea?
Best,
StevenAfter some further internet research here is a claim I found that appears to make sense (Original Poster: http://www.chevelles.com/forums/showthread.php?t=21662)
[i]If you are using plain steel shim head gaskets, then I have used the copper spray with good luck.
If you are using higher end MLS gaskets (Cometic, Fel-Pro, Victor-Reinz) they are coated (typically with Viton) and need to go on DRY.
Keep in mind though, with either MLS or Steel Shim, if the surface finish on your heads and block aren’t up to snuff (read: very smooth, 32 RA or smoother) don’t be surprised if you have leaks! The steel shim and MLS gaskets are not very forgiving and do not take kindly to rough surfaces.
[/i]I will likely go dry then as I do know there is a rubber material on around the coolant/oil/piston areas
I do not recommend the use of copper spray on the head gaskets. Let the gaskets do the work and you should be fine. The factory didn’t put it there, why should you?
I do no recommend using RTV in place of an ‘o’ ring. You might take them to the parts store to see if they can ‘match them up’. Sometimes they have a bin with different sized ‘o’ rings that they can match up.
Good luck and keep us posted.
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