sschultze09

I just installed a cat by-pass and noticed the spark plug wires are very close by. I have not had the lower shield since I bought the car. I never worried about it because my cat had the heat shields installed. Are the spark plug wires going to be ok or get too hot? Should I track down a lower shield and install it to be safe. Just wondering what you guys would do if anything.
TIA

Cosmos99

IIRC when I installed mine there was no way to bolt the factory cat heats shield to the new bypass. I also figured that the bypass does not get as hot as a cat and since the muffler on the other side didn't have a heat shield I left it off. It's been almost 2 years and 11k miles with no issues.

crg53

I wouldn't worry too much about the cat heat shield, but I would put on the heat shield that fits onto the engine tin covering the spark plug wires and valve covers, more so to keep everything clean and dry.

RSAErick

I would at least install the heat shields that attach to the engine tin.

I would fully expect that there is increased deterioration of the rubber wires taking place with so much heat to contend with. New wires are $500+, so I wouldn't want to replace them any more often than necessary. And I also wouldn't want to troubleshoot engine misfires that may be caused by wire degradation either.

"An ounce of prevention..."

Marc Shaw

Just get the cat bypass ceramic coated and skip the heat shields.

Marc

sschultze09

Thanks guys for your responses. I didn’t mean installing the old heat shields off of the cat I meant the lower heat shield that is part of the engine tin like Steen and Erick mentioned. I just spent the $500 on new wires that’s why I brought up this question. As far as ceramic coating I wouldn’t know where to get this done locally but will look into it. DC Automotive has the lower tin used for $100.00 and new they are crazy money.

RSAErick

FYI, I've also seen a product called 'Heat Sheets' or 'Heet Sheets' that attach over the valve covers/wires. I think that they may be titanium, and are explicitly for this purpose. Might be worth a look?

Merle

I'm pretty sure those shields that attach to the engine tin are for sound deadening and not a heat barrier.

sschultze09

Erick, I just looked into them and they were made by seine systems out of California but they currently have stopped producing them.

crg53

Yeah, and they DO keep dirt and moisture of the plugs/wires, and are also covered with heat deflecting tape.

Merle

I'm pretty sure the seal between the made when the plug wire is pushed into the valve cover keeps water away from the plug. Mine were so soaked with oil they weren't helping out with anything. This topic of heat shields used with a cat bypass has been covered many times on here and the concensus is that they are not necessary since the cat bypass pipe produces nowhere near the heat that's the cat does. If you feel like keeping the plastic boxes on that will do nothing for you but hold oil and heat near your engine than that's your choice. I ditched mine and have had no problems whatsoever and I'm using the same cat bypass that the op has.

PNine64

I do recall this topic coming up often but believed the engine tray should go, the heat shields on a cat bypass were not needed, and that the engine tin and the plastic covers that attach to them should stay. Personally, I like not having to worry about moisture, salt, or rocks wreaking havoc on my valve covers and plug wires.

Gus

I am getting ready to make some lower heat shields for my car as the old ones won't fit -
I will let you know the cost if you are interested.

sschultze09

Yes, Gus let me know what you come up with...Thanks

Gus

Steve - Just as an up date -
I have made the basic blank and need to fabricate the holes and the spark plug wire area - but this will give you an idea of the look of the aluminum shields