coolant leak
Thread Starter
Intermediate
Joined: Jun 2012
Posts: 33
Likes: 0
coolant leak
i own a 87 c4 and the other day i took it for a 20 min drive and the next day i find a puddle of coolant behind the back wheel on the passenger side, i cant find where the leak is coming from exact, help!
Safety Car
Joined: Mar 2005
Posts: 4,471
Likes: 1,224
From: Fredonia WI
2025 Corvette of the Year Finalist - Unmodified
2024 C7 of the Year Winner - Unmodified
2023 C4 of the Year Finalist- Modified
2020 C4 of the Year Finalist - Modified
2019 C4 of Year Finalist (performance mods)
2018 C4 of Year Finalist
You can check if the radiator hose clamps are tight. The overflow bottle is on that side -- is it really full?
Race Director
Joined: Apr 2002
Posts: 10,036
Likes: 346
From: Anaheim CA
I had this problem. Turned out to be a pinhole leak in the little rubber hose that goes from the back of the intake manifold to the heater pipes.
Come to think of it, I also had a leak at the water valve in those pipes.
Come to think of it, I also had a leak at the water valve in those pipes.
Drifting
Joined: Dec 2011
Posts: 1,439
Likes: 23
From: mesa az
Cliff I have a coolant leak. It seems to be a leak in my manifold somewhere ? I am having my mechanic take it off and replace all the gaskets. It seems I have water in the motor oil. My head gaskets are fine solid compression. Tested the coolant pressure and it held fine too. Yet I am leaking coolant and my plugs appear to be rusty. I have ruled out the head gasket so I am going forward with the manifold tear down. My 1988 has 194,000 miles. I checked the oil level and it is higher than normal. Must be water in the oil ? Would explain the rusty plugs appearance yes ? I was so worried the head gaskets were gonna be bad until the compression tests ruled that out. Please tell me your thoughts on this issue ?
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Race Director
Joined: Apr 2002
Posts: 10,036
Likes: 346
From: Anaheim CA
Heater core? Are you SURE? Mine leaked inside the car. It fogged up the windows as I was driving.
You REALLY REALLY don't want to replace a heater core unless you REALLY REALLY have to. The traditional joke is that the heater core was suspended from the ceiling at the factory and the car was built around it. Rated by many as the worst job to do on a Corvette.
As I said earlier, I found a pinhole leak in the bottom of this rubber hose:
And this guy leaked on me (you can see rust stains on the wires):
You REALLY REALLY don't want to replace a heater core unless you REALLY REALLY have to. The traditional joke is that the heater core was suspended from the ceiling at the factory and the car was built around it. Rated by many as the worst job to do on a Corvette.
As I said earlier, I found a pinhole leak in the bottom of this rubber hose:
And this guy leaked on me (you can see rust stains on the wires):